Successful recovery efforts have strengthened populations of kākāpō, a large, green, flightless parrot with an owl-like complexion endemic to New Zealand and once on the brink of extinction.

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Endemic to the island country of New Zealand, the kākāpō is a large, green, flightless parrot with an owl-like complexion. Regarded as a taonga species (treasured, prized) to Ngāi Tahu, the principal Māori iwi (tribe) of the South Island, the kākāpō evolved to be a distinct species approximately 30 million years ago, thus holding historical, cultural and spiritual significance locally. 

Although once widespread across mainland New Zealand, the introduction of hunting practices, invasive predators, and habitat loss caused rapid declines in kākāpō numbers, resulting in the species being deemed “Extinct in the Wild” by 1994. Nevertheless, recovery efforts have been successful in protecting and gradually strengthening remnant groups, with the current population of 236 kākāpō residing within fenced sanctuaries and on predator-free islands across New Zealand. 

Appearance

Kākāpō are incredibly unique, with the species owing its distinctive morphological and behavioral characteristics to the particular evolutionary context and selective pressures present on the Pacific islands prior to European colonization. 

Having evolved without the presence of mammalian predators, the kākāpō developed a large, robust torso physique well adapted to terrestrial life at the expense of flight capabilities. As a result, kākāpō are the heaviest species of parrot, with males weighing up to 4 kilograms and females weighing between 1-2.5 kilograms. Measuring between 58 and 64 centimeters in length, this remarkable bird uses its wings for balance and small falls, with only lighter females managing glides of 3-4 meters.

Easily identifiable by its moss-green coloration, brownish yellow mottling of feathers, and grey hooked beak, the ground-dwelling kākāpō’s plumage evolved to blend in with surrounding forest foliage, diverging from the distinctive bright, vivid pigments that typically adorn parrot species. Historically threatened only by large, diurnal birds of prey, the kākāpō’s camouflaging coloration, coupled with its tendency to freeze in the face of danger, allowed it to evade aerial predators with relative ease. With short, solid legs and large feet, kākāpō are strong hikers and climbers, using their hooked bills, a characteristic feature of parrot species, to climb up 20 meter tall rimu treesand parachute down with their wings.

Also known as the owl parrot, or night parrot in Māori, the kākāpō’s owl-like complexion is a result of morphological adaptations that support a nocturnal lifestyle. As one of only two species in an otherwise entirely diurnal group to evolve nocturnal behavior, the kākāpō has forward-facing eyes, lending a larger binocular visual field for enhanced light capture, and a flat facial disc of textured feathers. These direct sounds towards its ears, enabling this extraordinary species to navigate the forest floor at night. Typically walking with its head low to the ground, the kākāpō also possesses specialized, sensory feathers around its beak that act as vibrissae (whiskers), utilizing them to sense their environment in the dark.

Diet

The kākāpō is a herbivorous species with a diverse diet that varies seasonally, typically consuming leaves, stems, roots, bark, buds, flowers, fruit, nectar, seeds, and bulbs. Opting for new growth in the summer and spring months, and returning to bark and tubers in the autumn, the historic abundance of terrestrial food sources in New Zealand has been deemed a significant factor in the kākāpō’s evolution towards flightlessness.

Feeding almost exclusively on key species when plentiful, the kākāpō’s most crucial food source is the rimu fruit tree, with mass-fruiting events indicating the start of the kākāpō’s breeding season. The vitamin D and calcium found in the rimu fruit are essential to egg production and the growth of chicks, however mass-fruiting only occurs every two to five years. 

Identifiable by crescent-shaped chew marks, kākāpō are browsers, consuming high-fiber food sources rich in vitamins, minerals and protein. Unlike fellow parrot species that rely on a gizzard to digest food, the kākāpō has a finely ridged, concave upper mandible that grinds and compresses foliage as it passes through the bill from bottom to top, extracting nutrients and leaving behind a ball of indigestible fiber hanging from the plant.

Habitat and Behaviour 

Kākāpō have been a distinct species for approximately 30 million years, and were once widespread on mainland New Zealand prior to human colonization, inhabiting a wide range of vegetation types throughout the majority of the North, South and Stewart Islands. A model of kākāpō fossil records suggests that the species occurred in Hall’s tōtara, mountain beech, and broadleaf forests with mild winters and medium to high levels of precipitation. 

Kākāpō disappeared from New Zealand’s North Island by 1930, and from Fiordland towards the late 1980s. A declining population of less than 200 birds was found on Stewart Island in 1977. By 1995, there was a single kākāpō left on the mainland, and a mere 50 birds on Stewart Island. Throughout the 1980s and 1990s, all known kākāpō were transferred to Whenua Hou/Codfish Island, Maud Island, and Hauturu/Little Barrier Island, where protection measures and predator eradication campaigns were carried out. 

Today, kākāpō are only located on the protected offshore islands of Whenua Hou/Codfish Island, Pukenui/Anchor Island, Te Kākahu-o-Tamatea/Chalky Island, and Coal Island/Te Puka-Hereka, as well as in the fenced mainland sanctuary of Sanctuary Mountain Maungatautari, on New Zealand’s North Island.

As nocturnal foragers, kākāpō sleep in ground or tree-top roosts during the day. When disturbed or faced with danger, kākāpō freeze and rely on their coloration for camouflage, which has historically served as an excellent defense mechanism against avian predators that rely on sight. However, the introduction of mammalian, cathemeral predators that utilize their sense of smell to hunt, such as cats and stoats (short-haired weasels), rendered the distinctive-smelling, flightless kākāpō an easy prey source after European colonization. 

Although widely regarded as a solitary species, recent studies indicate that female kākāpō are occasionally found with young birds in groups of two to four individuals, socializing in the same tree or gathered near a food source. The kākāpō is the world’s only lek-breeding species of parrot, with mature males and females meeting solely to mate. Breeding occurs once every two to five years, coinciding with the superabundant seeding or fruiting period of key, high-nutrient food sources, such as rimu and pink pine trees. Each male kākāpō will form a track-and-bowl system, consisting of a network of tracks emanating from shallow, bowl-shaped pits in the ground, with tracks connecting two to three, or up to 10, bowls. The location of these systems remains fixed. From here, the male emits deep, low-frequency ‘boom’ sounds every one to two seconds, interspersed with metallic “ching” sounds to help navigate females towards them. Male mating calls can last roughly eight hours, every night for two or three months between early January and March. 

Once kākāpō mate, males are not involved in incubation or parental care. Females will lay between one and four eggs in a sheltered nest, such as a hollow tree, a shallow depression in the soil, or a cave made from roots and rocks. Females will leave their eggs and chicks unattended each night to forage for food. Chicks typically fledge after 10 weeks, relying on their mothers for a further three to six months until they can forage independently. 

Kākāpō are amongst the longest-living avian species, with an average lifespan of 60 years but able to live up to 90 years in the wild.

Ecological Importance 

The kākāpō is an ancient, incredibly unique species native to the forests of New Zealand, holding significant cultural significance and ecological importance to the ecosystems it inhabits. Regarded as a “super-generalist” herbivore, consuming a wide variety of plants, fruits, and seeds, the kākāpō plays a crucial role in maintaining the health and vitality of forests through seed dispersal, supporting the regeneration of native vegetation and creating a balanced ecosystem. A distinct species for 30 million years and once widespread across New Zealand, the ecological consequences of the kākāpō’s extinction would not be immediately discernible, yet undoubtedly inevitable. 

The evolutionary distinctiveness of the kākāpō, as the world’s only flightless, lek-breeding parrot, further represents a unique, fascinating result of natural history that could help scientists better understand evolutionary biology and conservation genetics. In 2021, a study containing the first genome sequencing and population genomic analyses of 49 kākāpō was published, shedding light on the effect of evolutionary forces on the species over time. The research is hoped to provide insights into the use of genetic tools in the conservation of long-term isolated endangered species. 

As mentioned, the kākāpō is a taonga species for the principal Māori iwi of the South Island, Ngāi Tahu, holding profound cultural, spiritual and historical significance and viewed as an animal to be treasured. Conservation efforts, which commenced 30 years ago and have had incredible results due to the combined work of iwi, rangers, volunteers, scientists and supporters, have become a totem of national identity and environmental conservation in New Zealand, with the kākāpō viewed as a flagship species to advocate the protection of native biodiversity.

Threats

Although once well-adapted to the particular, localized selective pressures of its native island, the kākāpō suffered catastrophic population declines with the human colonization of New Zealand, no longer able to effectively evade predation with the introduction of mammalian, terrestrial predators. Upon arriving in New Zealand roughly 700 years ago, the Māori began hunting kākāpō as a food source, as indicated by sub-fossil remains found in Māori middens (archeological cooking refuse piles), as well as for their feathers in the production of clothes. 

Two terrestrial mammals were also introduced by Māori settlers, the kurī (Polynesian dog) and kiore (Polynesian rat). Whereas kurī mainly served as companions and hunting aids, the kiore were brought as a source of food, rapidly becoming a widespread, invasive species that significantly affected Indigenous fauna. By the early 1800s, kākāpō were mainly confined to the central North Island and within forested areas of the South Island. 

Cats were introduced to New Zealand from 1769, initially intended as a means of vermin control aboard the ships of European colonizers. By 1820, feral cat populations, as well as two new species of rats, had settled on the islands, becoming widespread pests. As land was increasingly cleared for farming and grazing, mammals such as stoats and weasels were introduced as a biological control method against fast-growing rabbit populations that had destroyed pastoral land. It is believed that between 1883 and 1892, approximately 7,800 stoats and weasels were imported to New Zealand, with populations that had been released solely on rabbit-infested pastures quickly spreading across most parts of the North and South Islands. From 1851, several species of deer were introduced to New Zealand for recreational hunting, and in 1858 the first group of common brushtail possums were imported in an attempt to establish a profitable fur trade. With no natural predators, possum and deer populations rapidly increased, damaging native forests and depleting food sources.

Due to the kākāpō’s distinctive smell, which has been described as “like the inside of a clarinet case, musty and kind of like resin and wood,” coupled with the flightless bird’s tendency to freeze when confronted by danger, populations suffered rapid declines with the introduction of scent-driven, invasive predators. With a prolonged period of chick-rearing, resulting in a pungent-smelling nest, and given that kākāpō mothers leave their nests at night to forage for food, kākāpō chicks and eggs were rendered highly vulnerable to predation by rats. In a 1998 study, researchers found that over 50% of monitored adult kākāpō were killed each year by cats on Stewart Island. Once European colonizers became aware of the unique species, thousands of kākāpō were also captured for export to zoos, museums and for scientific study. 

As with many endangered species, reproductive failure is also a significant concern and impediment to population recovery. In addition to having irregular breeding seasons and a specialized lek mating system, kākāpō have exhibited high rates of reproductive failure, with 61% of eggs failing to hatch and 73% of these failed eggs showing no signs of development. Studies conducted on kākāpō bone fragments recovered from Māori middens and museum specimens indicate that the species once had asignificant degree of genetic diversity, yet centuries of population declines and isolation have inevitably resulted in a substantial level of inbreeding. Of 10 genetic lineages identified from bone fragments, only one remains today.

Due to the kākāpō’s small population size and low genetic diversity, disease has also been noted as a significant threat to the species’ recovery. In 2004, three juvenile kākāpō died of septicaemia caused by the bacterial infection erysipelas (Erysipelothrix rhusiopathiae), which had not previously been observed in the species. First identified in 2002, exudative cloacitis has affected at least 15 kākāpō, causing inflammation of the digestive and reproductive tracts, often resulting in infertility. Of most concern, however, was an outbreak of aspergillosis (a respiratory disease) in 2019 during a highly successful nesting season, which affected 21 kākāpō and resulted in nine fatalities among a total population of 147 individuals at the time. 

Conservation Efforts

The kākāpō is currently listed under Appendix I of the Convention on International Trade in Engendered Species (CITES), and is protected under New Zealand’s Wildlife Act of 1953, classified as “Nationally Critical” by the Department of Conservation.

In 1894, the government of New Zealand launched an initial attempt to save remaining kākāpō populations, with pioneer conservationist Richard Henry transferring several hundred kākāpō to a newly established, predator-free nature reserve on Resolution Island in Fiordland. Within six years, however, stoats had successfully reached the island and decimated the relocated population. 

By the mid-1900s, the kākāpō had become a forgotten species, rarely seen. Between 1949 and 1973, the newly established New Zealand Wildlife Service conducted over 60 expeditions to locate surviving kākāpō, focused primarily on Fiordland. However, only six males were caught and all but one died within a few months. In 1974, a further 18 males were captured on Fiordland, and in 1977, researchers made the remarkable discovery of approximately 200 kākāpō on Rakiura/Stewart Island. This population, which included females, had survived due to the absence of stoats, weasels and ferrets, yet predation by feral cats remained a significant threat. Therefore, between 1980 and 1997, these Rakiura kākāpō were transferred to three offshore island sanctuaries: Codfish Island/Whenua Hou, Maud Island, and Te Hauturu-o-Toi/Little Barrier Island. Although these islands were free of cats and stoats, rats prayed heavily upon eggs and chicks, hindering the species’ breeding success. By 1995, of 12 chicks that had successfully hatched across the three islands, only three survived, and the total kākāpō population had plummeted to a mere 51 birds. Recognizing the urgency of the situation, the Department of Conservation (replacing the New Zealand Wildlife Service) established the Kākāpō Recovery Programme in 1995, focusing on the eradication of predators and breeding support. 

In 1996, however, the New Zealand government faced the Ngāi Tahu tribe with regards to the colonial theft of their land, Codfish Island/Whenua Hou, which had been converted into a nature reserve in 1986 and rendered inaccessible to tribe members. As a result, the Ngāi Tahu Deed of Settlement was signed: Ngāi Tahu was given a distinct role in the management of Whenua Hou and in the conservation of the kākāpō, recognizing the tribe’s historic connection with the species as their kaitiaki (guardians). The Kākāpō Recovery Group was thus formed, incorporating representatives from Ngāi Tahu, the Department of Conservation, and the scientific community to develop holistic strategies for kākāpō conservation that unify both Western and Indigenous approaches to revive native, endangered species. 

Rats were eradicated from Codfish Island/Whenua Hou in 1998, and the island now serves as the center for Kākāpō Recovery in New Zealand, providing a similar habitat to that of Rakiura. The Department of Conservation maintains trap networks and employs detection strategies to prevent any future rat invasions on the island. 

In 2005, stoats were eradicated from Pukenui/Anchor Island, and the first kākāpō were transferred in 2005. Although the island is within swimming distance of the mainland for stoats, traps are regularly monitored to prevent disturbances. Te Kākahu-o-Tamatea/Chalky Island was subject to stoat eradication in 1999, and kākāpō were introduced in 2003. In 2020, a small breeding population was established, where scientists trial natural, low intervention population management strategies. Codfish Island, Anchor Island and Chalky Island all have abundant rimu forests that undergo mass-fruiting events every three to five years, supporting kākāpō breeding efforts. Imported items undergo a strict quarantine process prior to entering the islands, whereby clothes, food, gear, and the vehicle on which they arrived are disinfected and thoroughly checked to ensure the absence of any rats, insects, seeds or dirt.

In July 2023, the kākāpō returned to mainland New Zealand as a small, male population was translocated to the protected forest reserve of Sanctuary Mountain Maungatautari in Waikato, North Island. Enclosed by a 47 kilometre pest-proof fence, the sanctuary houses an ecosystem similar to that of a pre-human New Zealand environment, serving as a refuge for many of the country’s endangered species. This small population is under close observation to determine whether a larger group could flourish at the site. In May 2024, a number of male kākāpō were transferred to Coal Island/Te Puka-Hereka, which is home to a low number of stoats. Viewed as a trial site, conservationists hope to better understand whether low stoat densities pose a significant threat to kākāpō, and thus whether the island holds any potential of supporting a breeding population.

The continued and growing need for new, suitable kākāpō habitats is largely reliant on the success of initiatives such as Predator Free Rakiura and Predator Free 2050, with the Kākāpō Recovery Group ultimately aiming to return kākāpō to their historic range across New Zealand without the need for population management. At present, all kākāpō are radio-tagged and monitored throughout the year, and nests are closely observed during breeding seasons. Once a year, the Department of Conservation carries out a health check on each kākāpō, noting their weight, moulting condition, and any signs of injury or illness, later uploading this information onto a national database. Chicks are examined every one to five days while nesting, every two to six weeks for five months once fledged, and every three months until they reach the age of two. Kākāpō also receive supplemental feedings most years to ensure that the birds remain in good reproductive condition, as well as to increase egg production and support chick-rearing. Artificial insemination has additionally proven a successful tool in conservation efforts, boosting fertility by increasing the number of eggs produced, and improving genetic diversity by pairing birds that are likely to be genetically compatible. 

Once a female kākāpō has laid her eggs, some may be removed for artificial incubation, which replicates the temperature and humidity of a nest, and replaced by “smart eggs” to prepare the mother for when the chick is returned once hatched. If the mother has too many chicks, or if a chick falls ill or appears underweight, they are removed from the nest and hand-reared. Hand-reared chicks are kept together, and returned to the wild at the age of four months to avoid negative imprinting, whereby the bird identifies with humans and refuses to mate with its own species. As of early 2024, 69 kākāpō were hand-reared and returned to their natural habitat with a survival rate of 100%. It is hoped that effective nest management strategies and supplementary feedings will reduce the need for hand-rearing further by increasing the health of kākāpō, thereby allowing the chick-rearing process to occur as naturally as possible.

Due to the fact that the kākāpō population plummeted to a mere 51 birds in 1995, creating a genetic bottleneck, most kākāpō today descend from the same isolated island population. As a result, the species suffers from extremely low genetic diversity, having undergone a significant degree of inbreeding. It has been determined that approximately half of the current kākāpō population carry the same set of disease resistance genes; should a disease to which that particular genome type is susceptible spread across remaining kākāpō groups, the entire population could go extinct. Inbreeding has also been noted as a potential cause for the kākāpō’s low fertility rates, with approximately 61% of kākāpō eggs having failed between 1981 and 2019. As a result, genomic studies have been at the forefront of kākāpō conservation in recent years. 

In 2015, the Kākāpō125+ project commenced with the aim of sequencing the genomes of every living kākāpō. As of 2018, the genomes of 169 to 171 kākāpō have been sequenced, providing conservationists with insights into genetic signatures for diseases, genetic bases for fertility, including sperm quality, clutch size, incubation and hatching success, and genetic management, including the viability of offspring resulting from artificial insemination. In 2019, the largest kākāpō breeding season to date occurred, allowing scientists to determine whether the kākāpō’s high rates of hatching failure were due to fertilization failure or embryo mortality, with the differentiation deemed critical to creating effective breeding management strategies. The results of the study, published in 2021, demonstrated that early embryo mortality is the main reason for kākāpō reproductive failure, contradicting previous assumptions that infertility was the primary cause. Early embryo mortality was found to be driven by inbreeding depression on early survival, with the study highlighting the potential importance of artificial insemination as a management tool for wild kākāpō populations. 

On February 14, 2026, the first kākāpō chick of the breeding season hatched on Pukenui/Anchor Island, marking an incredible step in kākāpō conservation. With the last breeding season having occurred four years ago in 2022, there have been 187 eggs laid this season, 74 of which are fertile. Although not all eggs will hatch and not all chicks will survive to fledge, the inspiring efforts of the Kākāpō Recovery Group, through the Kākāpō Recovery Programme, have demonstrated the remarkable results that can stem from cooperation between government bodies, native iwi, rangers, volunteers and the scientific community to protect a species that was once on the very brink of extinction.

Featured image: Jake Osborne/Flickr.

Check out more from our Endangered Species Spotlight series

From its appearance and diet to the threats it faces and conservation efforts, here’s everything you need to know about the Malayan tapir.

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The Malayan, or Asian, tapir is one of four extant species of tapir, and the only one found outside of the Americas. Closely related to Rhinocerotidae (rhinoceroses) and Equidae (zebras and horses) by virtue of their shared order, Perissodactyla (odd-toed ungulates), tapirs have just three toes on their hind legs and sport long, prehensile snouts that support a herbivorous diet. 

Although the species has a relatively wide distribution range, found across Malaysia, Indonesia, Myanmar and Thailand, the Malayan tapir has suffered significant population declines due to habitat loss and fragmentation, frequently falling victim to poaching, snare traps, and the effects of urban development. As a result, this unique mammal has been classified as ‘Endangered’ under the IUCN Red List since 1986.

1. Appearance 

Malayan tapirs are the largest of all four tapir species, with adults weighing up to 350 kilograms and reaching lengths of up to 2.4 metres. Their heavy, barrel-shaped bodies, thick skin and coarse hair are well adapted to navigate through dense vegetation in an effective, streamlined fashion. Fully matured individuals have black heads and forelimbs, a white middle, and black rear limbs; a unique colouration often likened to an Oreo cookie and hypothesised to serve as a form of camouflage, fragmenting the animal’s outline amongst forest shadows. Juveniles have brown hair with irregular white stripes and spots, a distinctive pattern similarly believed to aid with blending into forest foliage and dappled sunlight.

Tapirs have slightly elongated snouts, referred to as prehensile probosces, that function similarly to the trunks of elephants; flexible appendages that combine both the nose and the upper lip of the animal, which can be used to grasp things. Tapirs use their snouts to forage for food, plucking shoots, leaves and fruits from bushes, and as snorkels when submerged underwater.

Although tapirs are members of the order Perissodactyla (odd-toed ungulates), the Tapiridae are unique as they retain the ancestral structure of tetradactyl perissodactyls; they have three toes on their hind legs but four toes on their forelegs. Known as unguligrade locomotion, tapirs walk on the terminal bones of their toes, with enlarged toenails forming their hoofs. This adaptation increases the stride length and speed of tapirs, allowing them to run quickly in short bursts. To aid with traction when traversing mud, shorelines and hillsides, the toes of tapirs are splayed out.

2. Diet

A mixed and opportunistic feeder, the herbivorous tapir uses its prehensile snout for plucking leaves, shoots and fruits from branches and low shrubs (browsing), as well as for rooting around for fallen fruit and leaves within the undergrowth (grazing). Malayan tapirs feed on over 380 different species of vegetation, and have been observed breaking eight- to 10-meter long trees in order to reach tender leaves, buds and soft twigs. Primarily nocturnal, tapirs use their large bodies to wear down tunnel-shaped paths through dense vegetation, feeding in both wooded, grassy areas and around sources of water. The species also feeds on aquatic plants, spending a substantial amount of time in and around lakes, rivers and ponds.

As with all perissodactyls, the Malayan tapir is a herbivorous, hindgut fermenter. Also known as cecal digestion, hindgut fermentation refers to the digestion of food in the cecum (a pouch within the large intestine), primarily through microbial fermentation. This adaptation serves as a significant advantage to herbivorous species like the tapir, as it allows for better digestion and nutrient extraction from fibrous vegetation that is otherwise indigestible. Tapirs are thus able to survive in habitats with lower quality food sources, consuming large quantities of lower-nutrient food throughout the entire day and processing them rapidly.

3. Habitat & Behavior 

The Malayan tapir is found on the Indonesia island of Sumatra, across the Malayan Peninsula, along the western coast and peninsular south of Thailand, as well as in Myanmar, with the species’ occurrence divided into three sub-populations: Thailand-Myanmar; Southern Thailand and Peninsular Malaysia; and Sumatra. Although these sub-populations are relatively distinct and somewhat isolated across a wide distribution range, they cannot be genetically differentiated. 

Commonly referred to as “living fossils”, tapirs have existed since the Eocene epoch, approximately 56 million years ago, and have changed little since then, surviving multiple waves of extinction. Their unique lineage is amongst the oldest of extant mammals.

Malayan tapirs are primarily found in humid, tropical forests, both primary and secondary, as well as within wetland regions. They typically inhabit lower montane forests. However, populations in Malaysia and Sumatra have been found at altitudes of 1,600 to 2,000 meters. Studies on the Malayan tapir’s northernmost range in Thailand, which experiences a distinctive dry season, has indicated that the species has climatic limitations, with this population shifting from a wide-ranging altitudinal occurrence to being restricted to altitudes with high levels of humidity as seasons change. This need for humidity as a key habitat component may also explain why tapirs are not found in regions with a pronounced dry season of forests, such as Cambodia, Laos and Vietnam.

Nocturnal by nature, the Malayan tapir has poor eyesight and thus relies on its keen sense of smell to forage in the dark. Although the species has been widely described as solitary, displaying aggression towards other tapirs except for females with offspring or when in a mating pair, recent studies have suggested otherwise. 

Tapirs have been observed foraging in small groups or pairs, with some travelling across wider ranges than was previously believed. Intraspecific communication often occurs through high-pitched whistles, as well as through urine marking, which tapirs will use to outline paths throughout the forest and determine the presence of other tapirs to avoid confrontation. Despite their large build, Malayan tapirs are strong swimmers and spend a substantial amount of time in the water, keeping cool and feeding on aquatic vegetation. Able to use their elongated snouts as snorkels, tapirs will submerge themselves fully underwater as a means of predator avoidance. They are also seen wallowing in mud to remove skin parasites from their hides, such as ticks, and to prevent insect bites.

4. Ecological Importance 

Commonly referred to as “gardeners of the rainforest”, Malayan tapirs play an important role in supporting the vitality of their surrounding ecosystems. By consuming large quantities of vegetation on a daily basis, and given the wide variety of plant species that tapirs feed on, these hefty herbivores disperse numerous seeds through their faeces, supporting the growth of new plants and trees across the forest. This is especially important for the regeneration of slow-growing trees that sequester large quantities of carbon. 

Malayan tapirs also affect the structure and health of forest habitats by regularly pruning vegetation, creating pathways through dense foliage with their large, barrel-shaped bodies that other animals can use, and clearing spaces to support the growth of new plant life. 

The Malayan tapir is widely regarded as a keystone species with low functional redundancy, as the crucial, unique role that they play in seed dispersal and the modification of forest structures would not easily be adopted by another species in the event of the tapir’s extinction. Further regarded as an umbrella species, the conservation of tapirs and their natural habitat would benefit numerous other species found within the same ecosystems, such as deer, monkeys, wild cats, reptiles and birds. If Malayan tapir populations continue declining across their range, their absence is predicted to have significant impacts on the diversity, vitality and structure of the habitats and ecosystems they currently belong to.

5. Threats

The Malayan tapir has been listed as Endangered under the International Union for Conservation of Nature (IUCN) Red List since 1986, with populations having further decreased by over 50% since then. 

Largely driven by the widespread loss of prime forest habitat, the rate of decline in tapir populations is inferred to be proportional to the depletion of tropical rainforest cover in Southeast Asia over the same period of time. As forests are cleared for logging and resource concessions, palm and rubber plantations, as well as for agricultural lands, the development of the urban infrastructure like roads and human settlements necessary to support these businesses create secondary, indirect threats to Malayan tapirs, such as road accidents, easier access for poachers and snare trappers, and the fragmentation of remaining habitats.

With the species’ total population estimated at fewer than 2,500 mature individuals, and with a predicted decline of approximately 20% in the next 20 years, the Malayan tapir faces a substantial risk of extinction without the implementation of effective conservation measures.

The large-scale conversion of primary forests into palm oil plantations throughout Southeast Asia has had significant, devastating effects on the ecosystems they inevitably destroy in the process. 

Tapirs are unable to survive within these single-crop habitats due to the complete loss of biodiversity and depletion of food sources they cause, with the extensive use of pesticides and herbicides further exposing the species to the threat of poisoning through contaminated water or food. Prone to wandering and to displacement by fellow tapirs, individuals that venture into plantations and urban areas are at greater risk of injury or death from human retaliation, vehicle collisions, poaching, and accidental snare trapping. 

Studies have found a strong correlation between the development of plantations and the increase in tapir mortalities by road accidents. Logging activities, however, appear not to cause a significant disturbance to tapir populations. Recent studies in Malaysia have found tapirs in a wide range of forest types, including logged, disturbed, and isolated areas. It is believed that this is due to the tapir’s preference for feeding in open areas with greater availability of browsing vegetation.

Notably, some regions across the Malayan tapir’s endemic range have reported success in reducing their annual rates of deforestation, according to the IUCN. In Malaysia, approximately 43% of the country’s total forest cover remains undisturbed and appears stable, half of which is deemed to be tapir habitat. In Thailand, although 40% of forests are found outside of protected areas, these are mainly degraded habitats, with most primary forests falling within protected areas and the majority of the region’s tapir population occurring within these well-protected national parks and reserves. Indonesia, which stands as one of the world’s largest palm oil producers, witnessed a 64% drop in deforestation rates between 2015 and 2017, as well as between 2020 and 2022. 

Nevertheless, despite these promising trends, and although the potential of sustainably grown palm oil has garnered increasing awareness over the past two decades with the Roundtable on Sustainable Palm Oil having been founded in 2004, the global scale of forest loss has actually accelerated in recent years. 

In Myanmar, a mere 5% of the country’s total land area is protected forest. Myanmar’s tapir population is largely restricted to the forests within the Tenasserim Range, which, until recently, were inaccessible to conservationists due to the years of civil unrest that the country has suffered. In 2002, the government proposed the creation of two protected areas within the Tenasserim region, Taninthayi National Park and Lenya River Wildlife Sanctuary, although only the latter is currently protected from forest clearance.

Exacerbating the devastating impacts of deforestation is the fact that remaining viable habitats are discontinuous and highly fragmented, leaving small, isolated tapir subpopulations vulnerable to inbreeding and genetic bottlenecks. 

In Sumatra, approximately 50% of remaining forests are currently inaccessible to Malayan tapirs, falling outside of their natural range. Along the Thai-Myanmar border, most subpopulations are estimated to hold no more than 50 to 100 individuals, with smaller, highly isolated groups only numbering ten to 15 individuals. At present, these subpopulations have no way of travelling to other suitable habitats or protected regions to breed with other groups, and will therefore inevitably cause their genetic diversity to decline over time. 

In 2009, the Federal Government of Malaysia proposed the creation of a “Central Forest Spine”, aimed at restoring and strengthening the connectivity between main forest regions and conservation landscapes on Peninsular Malaysia. Nevertheless, studies have found that subpopulations in the southern states, such as Johor, Negeri, Sembilan and southern Selangor, have become increasingly fragmented, thereby diminishing any chance of these habitats ever forming part of the proposed Central Forest Spine. Numbering a mere three to five individuals in some cases, these subpopulations have been deemed functionally extinct. 

A further, growing threat to Malayan tapirs in recent years has been hunting and indiscriminate trapping. As other species of large mammals decline across Southeast Asia’s forests, hunters have begun targeting tapirs as a food source, according to the IUCN, with tapir meat occasionally seen in local markets in Sumatra. 

Nevertheless, it is not a popular food amongst locals, and there is currently no evidence of systematic hunting practices for the species. It is believed that most tapirs sold for consumption are unintentionally captured as bycatch in snare traps, roadkill, or in conflicts with locals. Certain forest tribes within Thailand and Myanmar believe that the killing of tapirs is bad luck, whilst in Malaysia, consumption of tapir meat is forbidden by the national Islamic authority. When apprehended by local Malaysian authorities, most poachers appear to be from Cambodia, Vietnam and Thailand, with little known about their motives for capturing tapirs. In Sumatra, tapirs were previously caught in the wild and traded through zoos across Indonesia, occasionally sold to private buyers or to local meat markets as well, however this practice appears to have ceased in 2008.

6. Conservation Efforts

The Malayan tapir is currently listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and is protected across most of its endemic range by national legislation: Thailand’s Wildlife Preservation and Protection Act of 2019; Malaysia’s Wildlife Conservation Act of 2010; Indonesia’s Government Regulation No. 7 of 1999; and Myanmar’s Protection of Wildlife and Conservation of Natural Areas Law (1994). Although this unique mammal has been awarded the highest level of protection under each of these legislative measures, which criminalize the deliberate killing, trade, or capture of tapirs, they fall short of addressing the primary threats of habitat loss and fragmentation. As a result, they are limited in their capacity to fully protect, revive and maintain tapir populations.

At present, Malayan tapirs are amongst the least studied mammals in Southeast Asia, despite their long-standing status as an endangered species. While the effects of habitat disturbance, loss and conversion on the species are yet to be understood fully, there have been an increasing number of studies into the Malayan tapir’s ecology in recent years, with the results of these analyses potentially aiding in the creation of effective national conservation strategies.  

Due to their success in establishing comprehensive networks of protected areas, the tapir subpopulation of Malaysia and Thailand is perhaps the most accessible for monitoring and data collection. Thailand has established over 200 national parks, covering 17% of the country’s land area, with most of the Malayan tapir’s range falling within these protected areas. However, in a 2024 study, researchers found that tapirs occurred in higher abundances in Southern Thailand, despite a greater degree of habitat fragmentation.

The study posited that this was due to the fact that the major forest type in Southern Thailand is moist evergreen forest, with higher precipitation levels and elevations, where tapirs are able to remain away from the forest edges. The Western forest complex of Thailand holds larger, continuous forest habitats – although these are mostly deciduous forest, dry evergreen forest, and dipterocarp forest, with decreased elevational ranges and annual precipitation levels. While not the preferred habitat of Malayan tapirs, the Western forest complex is of critical importance to the biodiversity of Thailand as it is connected to transboundary forests within Myanmar, with researchers hypothesising that the significant allocation of conservation resources within this region has contributed to the low degree of habitat fragmentation observed. 

The study highlighted that, although smaller, fragmented areas are not necessarily better for tapirs, due to the risk of further habitat loss, depletion of genetic diversity, and proximity to urban infrastructure, the species’ persistence and abundance in these disturbed, fragmented or urban forests warrants greater conservation efforts to improve habitat quality and increase connectivity in these regions. 

In Malaysia, the Malayan tapir’s current distribution occurs primarily within protected areas in the four major forest complexes of the Central Forest Spine (CFS), with the remaining population persisting in isolated, fragmented forest areas outside of the CFS. In June 2022, a workshop was held for government bodies, zoos, higher education institutions, NGOs, and individuals in the field of Malayan tapir conservation to discuss the status of tapir conservation across three range states (Malaysia, Myanmar and Thailand), and provide the opportunity for cooperative action. It was revealed that, despite years of field research, there was insufficient data and information on Malayan tapir populations, their distribution, biology and ecology across their entire endemic range. As a result, the Malaysian Ministry of Energy and Natural Resources approved the Malayan Tapir Conservation Action Plan (2022), aimed at implementing conservation measures for the protection of the species, such as: habitat and population management; the enhancement of law enforcement; education and public awareness initiatives; and further research studies.

Since the implementation of the plan, the Department of Wildlife and National Parks of Peninsular Malaysia (PERHILITAN) has responded to public complaints about tapirs in an effort to minimize conflict, translocating displaced tapirs back to suitable forest habitats to reduce the risk of human retaliation or road accidents. The Malaysian Public Works department has created elevated roads and extended bridges that facilitate the movement of wildlife via underpasses to avoid collisions with vehicles, which appear to have benefitted tapirs, sun bears, guar, elephants and tigers. 

Having identified the Sungai Dusun Wildlife Reserve as a prime habitat and potential sanctuary for released tapirs, the PERHILITAN has begun replanting the Malayan tapir’s preferred plant species within the reserve to further support population increases and prevent instances of displacement caused by searches for food sources. 

In a joint patrolling initiative between the Malaysian Army, police force, and PERHILTAN, the Biodiversity Protection and Patrol Programme aims to combat instances of poaching by conducting monthly snare operations and patrols of protected forests. The PERHILITAN has further established the Institute for Biodiversity, which conducts education and public awareness programmes that are aimed at promoting a positive perspective on environmental conservation and biodiversity. In addition to celebrating World Tapir Day annually, collaborative efforts with the Malayan Nature Society have resulted in education initiatives being implemented in schools, universities and local communities. Lastly, research studies conducted by PERHILITAN, in collaboration with the Copenhagen Zoo and Universiti Putra Malaysia, aim to shed light on the population, distribution, feeding habits, behaviour, ecology, and genetics of the Malayan tapir.

According to the IUCN, Indonesia in 2013 developed a National Tapir Conservation Action Plan with several primary aims, including population monitoring; habitat protection; community engagement and education; population management in fragmented habitats, and research. Although there is little evidence of its implementation or efficacy across the country, aforementioned reports of decreased deforestation rates across Indonesia are a promising indication of governmental efforts. 

The establishment of the Round Table for Sustainable Palm Oil (RSPO) has also influenced significant changes in the practices of palm oil businesses across Indonesia and Malaysia, with many committing to maintaining the environmental protection and conservation standards necessary to achieve an RSPO certification. The Indonesia Sustainable Palm Oil (ISPO) certification aims at promoting economic, environmental and social sustainability through good agricultural practices, resource management, biodiversity conservation, social responsibility, and transparency. Malaysia also holds its own national certification system (MSPO), supporting similar initiatives. Together, Indonesia and Malaysia account for over 80% of the global output of palm oil. By 2022, 25% of Indonesia’s total plantation area achieved ISPO certification, and by 2024, 88% of Malaysia’s total palm oil production was MSPO-certified. In 2023, approximately 20.1% of the global palm oil production was certified sustainable palm oil, with 79.8% contributed by Malaysia and Indonesia.

Given the fact that deforestation and habitat fragmentation persist as the Malayan tapir’s primary threats, current trends in sustainable palm oil production constitute a positive step towards a growing global interest in habitat conservation and the protection of biodiversity across Southeast Asia. With the continued implementation of conservation measures that are consistently improving by virtue of a greater understanding of the Malayan tapir, this unique species can be revived throughout its endemic range, thereby protecting the vitality and biodiversity of the ecosystems they call home.

How You Can Help

• Opt for products that contain and promote sustainable palm oil. Keep an eye out for products that use the RSPO trademark, or display the label of “RSPO certified” or “this product contains certified sustainable palm oil”.
• Reduce your use of paper and wood. Go paperless wherever possible, opt for reusable products, and ensure that any wood products that you purchase come from responsibly managed forests. Organisations such as the Forest Stewardship Council (FSC) certify responsibly sourced wood products. 
• Spread the word. Educate yourself and those around you about the importance of the Malayan tapir, the threats they face, and engage with conservation organizations that support the protection of these incredible mammals across their range.

Featured image: Allison Giguere/Flickr.

Found across the North American and Asian coasts of the Pacific Ocean, the sea otter is one of the smallest, and perhaps the most endearing, marine mammals in the world.

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As with most members of the Mustelidae family, the sea otter has incredibly dense fur, made up of approximately one million hairs per square inch of skin. Although useful for insulation in absence of blubber, the sea otter’s characteristic coat made it the target of the maritime fur trade in the 18th century, forcing the species to the brink of extinction.

The subsequent implementation of international protective legislation in 1911 resulted in a significant recovery of sea otter populations across the species’ endemic range, reducing instances of hunting and persecution. However, pollution, oil spills, climate change and predation continue to pose a substantial threat to the vitality of sea otters, with the species therefore retaining an endangered status.

1. Appearance

The sea otter is the largest member of the Mustelidae family, which includes weasels, badgers and ferrets. Newborn sea otter pups measure in at a mere 25 centimetres and weigh just 1.4 to 2.3 kilograms. Northern sea otters tend to grow slightly larger than their southern counterparts, with northern males reaching a height of 152 centimetres and a weight of 45 kilograms, while southern males grow to around 120 centimetres in length and weigh 32 kilograms. Slight sexual dimorphism is observed within the species, as females are moderately smaller.

Sea otters typically sport a dark brown undercoat, with lighter brown guard hairs, and have webbed feet to aid with swimming. Their nostrils and ears are able to close when submerged underwater. With 850,000 to 1 million hairs per square inch of skin, the sea otter has the densest fur of any mammal. Comprised of two layers, an undercoat and long guard hairs, this water-repellent coat traps air to aid with buoyancy and insulation in absence of blubber. Sea otters maintain an exceptionally clean coat, often washing themselves after feeding to help retain its waterproof, insulating properties. 

2. Diet 

Since sea otters reside in coastal, shallow waters, their diet consists primarily of marine invertebrates, such as sea urchins, clams, muscles, abalone, crustaceans, snails, squid, and octopuses. Within newly reoccupied habitats in central California, sea urchins, abalones and rock crabs constitute the principal prey of local sea otter populations, whereas those found in soft-sediment habitats tend to consume clams and crabs. Sea otters found within the Aleutian archipelago of Alaska, however, regularly consume bottom dwelling fish, which constitute up to 50% of their diet during certain seasons.

Despite its relatively small stature, a sea otter’s prey size ranges from small snails, clams and limpets, to kelp crabs and giant pacific octopuses. When foraging for abalone, urchins and clams, sea otters tend to select larger prey over smaller options, with Californian populations often disregarding Pismo clams smaller than 7 centimeters in diameter. Sea otters have been found to consume upwards of 100 different species of prey and have an incredibly high metabolism, with a daily food intake of 25-40% of their body weight in order to keep them warm. 

Whilst foraging for food underwater, these marine mammals use loose skin under their armpits to act as a pocket for food storage. Clams, which burrow in soft sediment, are excavated through digging. Males tend to forage at a maximum depth of 82 metres, whereas females only descend to 54 metres. Typically feeding in the morning and afternoon, sea otters float on their backs at the surface of the water to eat. They are amongst the few animals that have been observed using tools to access food sources; for prey such as clams and abalone, sea otters are often seen using a rock to strike and break open hard shells.

3. Habitat & Behaviour

Sea otters are a costal species and therefore use a range of near shore marine environments, foraging primarily in waters less than 30 metres in depth and within a kilometre of the shoreline. Predominantly associated with rocky, intertidal habitats that support kelp beds, sea otters utilise kelp as anchorage to avoid floating away with ocean currents when resting, indicating the importance of kelp canopy as a habitat component. Some have even observed that dense kelp canopy can help otters with predator avoidance, evading shark bites with greater ease. Nevertheless, the species has also been known to spend time in areas with soft-sediment, devoid of kelp, where the substrate consists of mud, silt or sand rather than rocks.

Habitats that offer protection from ocean winds and swells, such as barrier reefs, kelp forests, rocky coastlines, inlets, bays and estuaries, are of critical importance to sea otters as well. Although this marine mammal tends to remain within a small home range and displays high site fidelity, some sea otters, predominantly males, do carry out migrations and long distance movements at certain times of the year.

Sea otters are almost exclusively aquatic, though in some regions they may come ashore to rest or sleep. Known for their characteristic floating, sea otters are incredibly buoyant due to the air trapped within their dense coats, allowing them to sleep, feed, play, and even nurture their young while floating on their backs. These mammals are highly social and are only weakly territorial, with instances of aggression or fighting deemed rare. Males and females float in separate groups of between 10 and 100 individuals, known as “rafts”, often holding hands to prevent separation. 

Sea otters are the only species of otter to give birth whilst in the water, with females typically delivering a litter of one. The coats of newborn pups trap sufficient air to prevent them from diving or becoming submerged underwater, with mothers often wrapping their young offspring in kelp when leaving to hunt and forage. Infants are taught to swim and search for food at four weeks old, and remain dependant until the age of six to eight months.

4. Ecological Importance

Despite their small stature, sea otters are regarded as a keystone species, meaning that they have a profound effect on marine ecosystems and play a crucial role in maintaining the vitality of their habitats.

As mentioned, sea otters rely heavily on kelp forests to provide anchorage when floating in rafts and for foraging. A large proportion of their prey sources reside within kelp forests, such as urchins, crabs, and barnacles. If left unchecked, sea urchin populations can grow rapidly and overgraze on kelp, consuming it faster than it can be replenished and eventually destroying the forest habitat. This creates “urchin barrens”, where nothing but sea urchins are able to grow due to their abundance. Kelp forests, found within coastal ecosystems, sequester significant amounts of atmospheric carbon and prevent it from entering the atmosphere. These marine forests are capable of storing 20 times more carbon per acre than those found on land, with research suggesting that seaweed forests sequester tens of millions of metric tons of carbon yearly within the deep ocean globally. The degradation or loss of kelp forests could thus have grave effects on the levels of atmospheric carbon, highlighting the importance of the trophic function that sea otters serve.

In addition to kelp forests, sea otters tend to hunt for prey, such as crabs, within seagrass meadows and eelgrass beds. Seagrass also sequesters atmospheric carbon, with the flowering plant able to capture carbon 35 times faster than tropical rainforests. By controlling the abundance of crabs within these habitats, crabs are prevented from overpopulating and consuming too much of their prey, which include snails and slugs. Rather than feeding on seagrass, these mollusks graze on algae and other epiphytes that grow on seagrass, performing a “cleaning” service. By removing surface algae, grazing mollusks allow the seagrass to absorb sunlight and grow with greater efficiency, enhancing its ability to act as a carbon sink. 

In addition to serving as blue carbon ecosystems, kelp forests and seagrass meadows are the preferred habitat of a range of marine species that rely on them for shelter and sustenance, including sea otters. These marine mammals are therefore regarded as an indicator species for coastal ecosystems, as the health, vitality and population dynamics of sea otters are indicative of the health of cohabiting species and the ecosystems they share.

5. Threats

Once widespread across the North Pacific Rim, from the coasts of Japan through to Russia and Alaska, down to California and Mexico, sea otters were estimated to have a global population of 150,000 to 300,000 at the start of the 18th century.

Once Russian explorers reached Alaska in 1741, sea otters became the target of an extensive commercial harvest that lasted 150 years until the species was left at the brink of extinction. By 1911, once the International Fur Seal Treaty was implemented, it is hypothesised that a mere 2,000 sea otters remained across 13 remnant colonies. The consequence of this near extirpation was noted in the 1970s by James Estes, a marine ecologist who observed a dramatic loss of kelp forests in absence of sea otters when diving in Alaska. Although the maritime fur trade no longer poses a threat to sea otters, these marine mammals are still vulnerable to pollution and oil spills, disease, entanglement, climate change, and predation.

At present, oil spills are regarded as the most significant anthropogenic threat to sea otters. With no blubber to provide insulation, sea otters rely heavily on their dense coats to keep them warm. When exposed to oil, however, their fur loses its insulating properties and renders sea otters extremely vulnerable to hypothermia and other health complications. Oil accidentally ingested while grooming can further cause illness and gastrointestinal disorders, disrupting the sea otter’s ability to absorb nutrients and often leading to malnutrition and death. Inhalation of oil has also shown to cause lung damage in the species.

In 1989, the tanker vessel Exxon Valdez spilled approximately 42 million litres of crude oil into the ocean in Prince William Sound, Alaska. Within seven months of the event, nearly 1,000 deceased otters were recovered in the spill area, however it is estimated that the total number of sea otter mortalities resulting from the spill ranged from 2,650 and 3,905. Research conducted in the years since the disaster suggests that the Exxon Valdez oil spill had continuous and enduring consequences on sea otter populations, with an increase in mortality rates seen in otters that were four to five years old, or older, at the time of the spill. The study further found that until at least 1996, otters born after the event were also affected negatively. This suggested that, although the direct impact of acute oil exposure accounted for the majority of long-term spill effects, sea otters were also affected indirectly through maternal influences or exposure to lingering oil residue. 

Other marine pollutants, such as run-off from the land, also have detrimental effects on sea otter populations, their habitats, and their prey sources. Run-off occurs when rainwater washes over urban or agricultural areas and collects pollutants as it traverses through waterways. These pollutants include: toxic chemicals used in agriculture, such as pesticides and fertilisers; heavy metals, such as mercury, lead and cadmium; tire dust; nutrients; sewage; and pathogens, such as bacteria and parasites. In addition to having direct, harmful effects on the health of sea otters, these pollutants can accumulate in the tissue of their prey sources, such as bivalves, resulting in the intoxication, infection, and eventual death of sea otters.

In 1996, researchers noted an increase in sea otter mortalities from infectious diseases, such as peritonitis, protozoal encephalitis, and toxoplasmosis, primarily in breeding adults. Caused by a parasite known as Toxoplasma gondii, toxoplasmosis is a disease that has plagued sea otter populations for decades as a significant cause of fatalities as well as a contributing factor to the stagnant recovery rates of sea otter populations in California. Felines have been identified as the definitive hosts of toxoplasmosis, shedding Toxoplasma gondii oocysts in their faeces, which is then washed into waterways and eventually reaches the ocean. These oocysts are either ingested directly by sea otters or contaminate the marine invertebrates they regularly consume.

Being a coastal species, sea otters often fall victim to destructive fishing methods that are prone to high bycatch rates and overfishing. Between the mid-1970s and early 1980s, a considerable number of sea otters were caught and drowned in gill nets and trammel nets within California. In 2003, research suggested that sea otter fatalities increased in the summer as commercial fin fisheries became more active in coastal regions. 

As sea otter reintroduction initiatives and range expansions continue to prove successful in California, with the once remnant population of 50 Californian sea otters having risen to approximately 3,000 individuals in 2018, concerns over potential conflicts with shellfish fisheries have also garnered increasing attention.

The reintroduction of sea otters to ecosystems that have been without the species for decades has naturally resulted in the reestablishment of historic feeding interactions. For commercial fisheries that have come to rely on these habitats in the interim, the reemergence of sea otters serves as a source of competition for common prey.

In Southern California, fishermen attributed decreases in abalone populations to the range expansion of sea otters, resulting in the proposal of a species management plan in 1968 to avoid overlap with the lucrative abalone trade. Upon the enactment of the Marine Mammal Protection Act in 1972, and once sea otters were given a status of “threatened” under the Endangered Species Act in 1977, the proposed management plan was rendered invalid as environmental conservation took precedence. Nevertheless, the potential perception that conservation measures negatively impact economic interests could result in decreased public support for the preservation of sea otters.

As ongoing studies continue to shed light on the effects of climate change on marine ecosystems, some potential, unquantified stressors to sea otter populations include ocean conditions becoming increasingly warm, acidic, and deoxygenated.

Warming oceans have shown to support the pervasiveness and range expansion of dinoflagellate phytoplankton, harmful algal blooms, and cyanobacterial blooms, which produce toxins such as saxitoxins, brevetoxins, ciguatoxins, domoic acid, and okadaic acid.

Although it is unclear whether the direct effects of toxin exposure on sea otters are acute or chronic, studies have shown that these neurotoxins accumulate in shellfish and induce shellfish poisoning in mammals that consume the contaminated bivalves. This leads to detrimental neurological, gastrointestinal, and cardiovascular symptoms.

Research has further indicated that as oceans become increasingly acidic due to excessive carbon dioxide absorption, saxitoxins will increase in toxicity as a result of biochemical changes associated with this lower oceanic pH level. Domoic acid exposure has been identified as a primary cause of death in southern sea otters, and has also been linked to the prevalence of cardiomyopathy in sea otter populations.

Northern sea otters in Alaska appear able to identify and avoid consuming clams that have accumulated low levels of saxitoxin in their tissue, however this decline in available prey sources will likely have a significant impact on sea otters in the future. This is especially true of populations relying on soft-sediment habitats, such as in the Kodiak archipelago of Alaska, where over 50% of a sea otter’s diet consists of butter clams. Bivalves that form their shells from calcium carbonate, such as clams, oysters and muscles, have also been decreasing in numbers due to ocean acidification. The increased acidity of seawater reduces the availability of carbonate ions, making it extremely difficult for bivalves to build and maintain their shells, and even causing some bivalve shells to dissolve.

A continuous, long-term study on the health, body condition, and causes of death of southern sea otters has suggested that the most common primary cause of death amongst the subspecies is shark bite mortality. Primary predators of sea otters include orcas, great white sharks, bald eagles, coyotes, and brown bears, with orcas having been linked to significant sea otter population declines in 1998 across the Western Gulf of Alaska and Aleutian Islands. With the preferred prey species of these macropredators, which include Northern fur seals, harbour seals, and sea lions, declining in numbers, the less preferred choice of sea otters become a primary target despite their lack of blubber.

6. Conservation Efforts 

With the enactment of the International Fur Seal Treaty of 1911 came an almost immediate end to the drastic population declines that sea otters had suffered for decades prior, marking the start of a long journey towards the species’ recovery. The subspecies Enhydra lutris nereis, known as the Southern or Californian sea otter, is listed under Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), while E. lutris lutris and E. lutris kenyoni are listed under Appendix II.

In the US, sea otters are awarded legislative protection under the Marine Mammal Protection Act of 1972 and were added to the Endangered Species Act in 1977, whilst in Canada they are managed under the Species at Risk Act. As such, it is illegal to purchase, sell or possess any part the endangered species or items made from its body parts.

Such conservation initiatives allowed sea otter populations to gradually increase in numbers, reaching a global estimate of 30,000 individuals by the mid-20th Century. Nevertheless, this figure represented a mere 10% of the species’ historic population estimate and sea otters remained absent from over 3000 kilometres of their former coastal range. Research indicated that the reluctance of sea otters to disperse from their home territory and traverse deep channels would render natural range expansions unlikely, therefore biologists initiated relocation initiatives in the mid-1960s. Healthy otters from the Aleutian Islands were transported to Southeast Alaska, British Colombia, Washington, Oregon and California. These reintroduction efforts were deemed extremely successful, with recorded population increase rates of 20% in some regions.

In Southeast Alaska, the initial population of 400 to 450 introduced sea otters has grown to approximately 25,000. A further 8,000 now inhabit the coast of British Colombia, having begun as a population of just 89 released individuals. This recovery is widely seen as an incredible achievement in marine conservation, as a species on the brink of extinction with fewer than 2,000 individuals now consists of a population of approximately 125,000 sea otters. 

Unfortunately, relocation efforts were not as successful in Southern California and Oregon. Of the small groups of sea otters transported from Alaska to the Oregon coast, none appeared to stay as scientists theorised the mammals had attempted to swim back to their home range and died. On San Nicholas Island in Southern California, a population of 125 introduced sea otters was reduced to just 12, however the remnant sea otters survived and have now grown to have a population of 150.

At present, Southern sea otters occupy a mere 13% of their historical range, remaining absent from the Oregon Coast, and consist of a population of approximately 3,000 individuals. Although this is a significant recovery, given that a single remnant colony of 50 sea otters remained in central California in 1911, the reintroduction of sea otters to Northern California and Oregon is regarded as necessary to strengthen genetic diversity and support the sustainability of sea otters by connecting southern and northern subspecies.

Research has indicated that there is sufficient suitable habitat to support reintroduction efforts, as the region represents the most extensive remaining gap in the once continuous historic range of the species. Now equipped with data collected from numerous successful reintroduction initiatives, scientists and conservationists can more accurately and efficiently determine areas along the Californian coast that would most benefit from the presence of sea otters, and where threats to reintroduced populations are minimal.

Despite the numerous benefits that sea otters bring to coastal marine ecosystems, reintroduction and range expansion initiatives have faced conflict with shellfish fisheries that ascribe decreases in the availability of shellfish to the reemergence of sea otters. In California, abalone and Dungeness crab fisheries have expressed concern about the potential competition they face with expanding sea otter populations. A report funded by the fishing industry in Alaska attributed a $28 million US dollar loss between 2005 and 2011 to sea otters. Yet, some have pointed to evidence of a historic coexistence between humans and sea otters, in the form of indigenous and archeological knowledge, as proof that conservation initiatives can account for the interests of all parties involved. 

At present, the Marine Mammal Protection Act and the Endangered Species Act allow coastal Native tribes to hunt sea otters, as long as they are used for sustenance or traditional handicrafts. This practice is monitored by the U.S. Fish and Wildlife Service through their Marking, Tagging and Reporting system, and the Marine Mammal Protection Act further requires the implementation of species recovery plans to ensure populations remain at viable levels. Some have noted the potential of this arrangement to serve as a form of population control for the species, as Native tribes have harvested up to 1,500 sea otters in some years and such a system has proven to support marine biodiversity over millennia of human-animal coexistence.

This holistic approach to conservation is evident in the ethos of organisations such as the Elakha Alliance, which aims to use scientific and socio-economic policy assessments that reflect the interest of Native tribes, governments, environmental groups and fishery representatives to determine the most effective strategies for the restoration and protection of sea otter populations in Oregon. If such initiatives prove successful in Oregon, they can be adapted and applied to other states and countries in order to minimise conflict between humans and sea otters, to better protect the species against the threats they still face, and to support the full recovery of sea otter populations throughout their entire endemic range.

How to Help

• Celebrate Sea Otter Awareness Week. Taking place between 21-27 September, Sea Otter Awareness Week is the perfect opportunity to inform those around you of the ecological importance of sea otters, the threats they face, and the small steps that people can take to help protect the species. 
• Opt for eco-friendly household cleaners. When buying household cleaning products at the market, opt for non-toxic and biodegradable cleaners that are better for the environment and marine ecosystems.
• Clean up pet waste properly. Felines carry the parasite, Toxoplasma gondii, that causes toxoplasmosis in sea otters. When disposing of cat faeces, avoid contaminating waterways that will end up in the ocean. Avoid purchasing “flushable” kitty litter. 

Featured image: Lee Jaffe/Flickr.

Acropora cervicornis is a species of staghorn coral that is predominantly found in Florida, the Bahamas, the Gulf of Mexico and the Caribbean. Comprised of approximately 400 different species of varying shapes and colours, staghorn corals are branching, stony corals that typically inhabit shallow tropical reefs and lagoons. As well as being some of the fastest growing corals in the world, staghorn corals are incredibly important for their contribution to reef growth and their role in providing habitats for marine life. In the Caribbean, Acropora cervicornis has played a fundamental part in the construction of coral reefs over the past 5,000 years and is widely regarded as one of the most important species in the region. However, an unprecedented disease incident in the early 1980s resulted in the loss of approximately 97% of the species’ cover, abundance, and occupied range. Remaining populations are generally isolated and display low colony abundance, thus increasing their susceptibility to threats of climate change, pollution, unsustainable fishing practices, and disease. With a population trend in punctuated decline, immediate restoration, conservation and monitoring efforts are needed to prevent the extinction of Acropora cervicornis.

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1. Appearance

Acropora cervicornis colonies are typically tan or light brown with white tips, deriving their colour from the zooxanthellae (algae) residing within their tissue. Stemming out from a central trunk at an upwards angle, the cylindrical branches of A. cervicornis are typically two to eight centimetres thick and can exceed two metres in length. Colonies often grow to form interlocking frameworks known as thickets, however A. cervicornis colonies tend to be more open and loosely packed than other species of Acroporidae. Although often confused for plants or rocks, largely due to their sessile nature (permanently fixed in one place; immobile) corals are, in fact, animals.

Corals are made up of hundreds of soft-bodied organisms known as polyps, which attach to a solid substrate (such as a rock or the dead skeletons of other polyps) and begin secreting calcium carbonate to create hard external skeletons, or corallites. As these polyp conglomerates continuously grow and reproduce, they begin to create these incredible hard, stony coral structures.

2. Diet

Most species of coral, particularly those inhabiting shallow, tropical waters, have two sources of food. Firstly, polyps have stinging cells, known as nematocysts, which they extend from out of their corallite to capture prey with, typically plankton. However, corals in shallow, warm environments derive most of their nutrition from the mutually beneficial, or symbiotic, relationship they have with the zooxanthellae (algae) that reside within the tissue of polyps. Zooxanthellae are plant-like organisms that utilise a coral’s metabolic waste products for photosynthesis. Having received these nutrients from the coral, the zooxanthellae then pass on some of the food they make to the coral. This symbiotic relationship, whereby corals receive food and oxygen in exchange for providing zooxanthellae with nutrients and shelter, plays a fundamental part in the rapid growth rate of tropical, shallow water corals. 

3. Habitat & Behaviour

The distribution of Acropora cervicornis spans the western Atlantic, from Mexico (Veracruz), southern Florida, and the northern Bahamas, down south across the Caribbean Sea to Trinidad and Tobago, including the insular and coastal reefs of Barbados, Venezuela, Aruba, Curaçao, Bonaire and Colombia. The species is unlikely to occur further north than Palm Beach County, Florida, or further south than Trinidad and Tobago. 

Acropora cervicornis requires clear, oxygenated, warm waters in order to thrive, and is therefore typically found in tropical, shallow reef ecosystems. Although the species displays a preference for upper to mid-reef slopes and lagoons in regions with low or moderate wave exposure, A. cervicornis has been observed in a range of coral reef habitats, including spur and groove formations, bank reefs, patch reefs, transitional reef habitats, limestone ridges, terraces and hard bottom habitats. Despite a depth range of one to 60 metres, the species is rarely found beyond 25 metres from the surface of the water.

Staghorn corals are simultaneous hermaphrodites, producing both eggs and sperm but not self-fertilising. Upon reaching sexual maturity, typically at around 18 centimetres tall or three to eight years, a staghorn coral will reproduce once a year by broadcast spawning eggs and sperm into the water column. Fertilised eggs will then develop into larvae, settling on hard substrates in the region or drifting hundreds of kilometres away to form new colonies. Studies have indicated that low rates of larval recruitment are typical for this species in the Caribbean, and that recruitment by sexual reproduction is relatively rare despite high levels of gamete production and release. Nevertheless, staghorn corals can also form new colonies when fragments of a coral branch fall off, reattach themselves to a hard substrate, and continue to grow.

More on the topic: Unpacking Florida’s Coral Reef Restoration Agenda

4. Ecological Importance

As mentioned, Acropora cervicornis is regarded as one of the most important species of coral in the Caribbean due to its extensive contribution to reef growth and its role in providing a complex habitat for marine life, thus safeguarding the biodiversity of marine ecosystems in the region. In abundance, staghorn corals further provide shoreline protection from waves and storms.

A. cervicornis, and coral reefs in general, also act as environmental indicators; their sensitivity to changes in the temperature, salinity, pollution levels, clarity, and pH levels of the waters they inhabit can inform scientists of any declines in the quality and health of ocean habitats. 

5. Threats

Although once found in high abundance across its endemic range, studies conducted on Acropora cervicornis have indicated a population decline of at least 80% over the past 30 years, with a current population trend in punctuated decline. As a result, the species has been classified as Critically Endangered under the International Union for Conservation of Nature (IUCN) Red List since 2008. Having suffered a staggering 98% decrease in cover, abundance and occupied range in the 1980s due to disease, and given its acute sensitivity to changes in environmental quality, remaining populations of A. cervicornis are currently isolated, display low colony abundance, and face a high risk of extinction. Major threats, which present themselves in a complex interplay, include climate change, pollution, and disease.

Perhaps posing the greatest threat to coral reefs across the world is the phenomenon of climate change, as rising ocean temperatures, disrupted pH levels, increases in the severity of storms, and possible shifts in ocean circulation patterns have had disastrous effects on ocean habitats over the past decades.

Coral bleaching occurs when ocean temperatures rise at least 1C above the normal seasonal maximum, subjecting coral reefs to increased levels of stress. As a result, coral evict the symbiotic algae (zooxanthellae) from their tissue, causing the coral to turn white. Although the coral remains alive in this bleached state, it has lost one of its primary sources of nutrition and is thus rendered highly susceptible to disease. If exposed to prolonged heat, the coral will eventually die from starvation or disease. Staghorn corals, and Acropora cervicornis in particular, appear to have an especially low resistance and tolerance to bleaching, taking longer to recover than other species.

In La Parguera National Reserve along the southwest coast of Puerto Rico, Acropora cervicornis displayed higher mortality rates due to temperature shifts and disease when compared to Acropora prolifera. After the occurrence of two global bleaching events in 1998 and 2010, the first mass, multi-year coral bleaching event took place between 2014 and 2017, where 30% of coral reefs experienced mortality-level stress. In April 2024, the National Oceanic and Atmospheric Administration (NOAA) detected evidence of a fourth, ongoing global bleaching event that commenced in February 2023. As bleaching events continue to occur with increasing frequency, coral reefs are prevented from ever fully recovering.

In addition to absorbing heat, the ocean absorbs approximately 30% of atmospheric carbon dioxide, acting as a carbon sink. As carbon dioxide dissolves in seawater, the water becomes more acidic, causing a drop in its pH level. With carbon emissions steadily increasing over the past 200 years, reaching a record annual emission of 37.4 billion tonnes of carbon dioxide in 2023, oceans across the globe have become 30% more acidic as a result of absorbing this excess carbon dioxide. Commonly referred to as ocean acidification, this change in the ocean’s pH has reduced calcification rates in reef-building organisms since calcium carbonate only forms when the ocean’s pH level sits within a specific range. Perhaps of greater concern is the possibility that this increasing acidity could also prompt existing corallites and sediment platforms to dissolve away, causing entire reefs to disappear. In a study published in 2018, researchers determined that there is a specific low point in oceanic calcium carbonate levels, below which coral reefs dissolve faster than they can build.

Compounding the vulnerability of coral reefs to disease and mortality is pollution. Runoff from agriculture, gardening, sewage, and costal development projects often contains toxins that affect the feeding habits, growth, reproduction, and ecological function of corals. This is particularly true of chemical and oil spills that occur in close proximity to coastal areas. Certain types of sunscreen can also cause extensive damage to coral reefs as they contain chemicals that induce coral bleaching, particularly in locations popular with snorkelling and diving. Excessive quantities of nutrients that are often found in fertilisers, such as nitrogen and phosphorus, further cause algal blooms that smother corals and affect the clarity of water. Deforestation and human development also typically intensify the process of soil erosion, which results in reefs becoming covered in silt. Since corals rely heavily on zooxanthellae to photosynthesise sunlight and supply them with nutrition, instances of prolonged declines in water clarity can expose coral reefs to the risk of starvation and disease. Additionally, pathogens found in untreated sewage can infect entire coral reefs, spreading into significant outbreaks.

Plastic pollution also poses a significant threat to oceanic habitats across the world due to the myriad of detrimental consequences it has on marine ecosystems. Large pieces of trash that wash into coral reefs from shorelines can damage coral branches or block sunlight from reaching the zooxanthellae within their tissue. Microplastics, often mistaken for food particles, are regularly ingested by corals as the smell of plastic is masked by bacteria found on the plastic. This bacteria, which is introduced to reef habitats from land or the ocean’s surface, may also carry pathogens that can cause widespread infection or mortality. Once ingested, most pieces of plastic are expelled after 48 hours, however some may become embedded within the corallite. These embedded pieces can then begin leaking toxic chemicals, affecting the health of the coral.

With issues of warming ocean temperatures, acidification, and pollution having deteriorated the health and vitality of coral reefs over the past few decades, coral disease has increasingly become a major threat to species worldwide. According to a 2018 study, the rising prevalence of coral disease and mortality can be linked not only to thermal stress, but also reduced water quality and clarity, nutrient enrichment, plastic pollution, and sedimentation due to dredging. The results of a survey conducted on 159 reefs across the Asia-Pacific region indicated that the likelihood of coral disease increases 20-fold once reefs are exposed to plastic. White-band disease (WBD) is thought to be the primary cause for the aforementioned Acroporid disease event that has affected Caribbean reefs since the 1980s, although the prevalence of WBD in A. cervicornis is currently low due to the limited distribution and abundance of the species. Regardless, a mere 6% of remaining A. cervicornis populations have proven resistant to WBD thus far.

Other major threats to A. cervicornis include: overfishing; unsustainable fishing practices, including dynamite fishing, chemical fishing, and dredging; changes in native species dynamics; human recreation and tourism; changes in the frequency and intensity of storms and hurricanes; as well as increased predation by Stegastes planifrons (Three-spot Damselfish), Hermodice carunculata (Bearded Fireworm), and Coralliophyllia spp. (coralivorous snail). Unsustainable fishing practices can have immense, long-term consequences on marine ecosystems, quickly altering the structure of a habitat from coral-dominated reefs to algal-dominated reefs (“phase shifts”) since the fish that consume algae are no longer around to maintain reefs clean and provide space for corals to grow. A. cervicornis is also among the most popular species of coral harvested for aquariums, with legal imports in the United States doubling from 2003 to 2009. Further hindered by restricted gene flow and low larval recruitment, A. cervicornis is unlikely to fully recover and regrow viable populations across its endemic range unless effective, holistic conservation, monitoring and repopulation efforts are put into place.

6. Conservation Efforts

When given the opportunity to recover in an ideal environment, coral have proven to be incredibly resilient. In addition to being listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), Acropora cervicornis has been further classified as ‘Threatened’ under the U.S. Endangered Species Act, as ‘Vulnerable’ under the Venezuelan national Red List, and as “Under Special Protection” under Mexico’s endangered species list. The species is also found in various marine protected areas (MPAs), such as the Florida Keys National Marine Sanctuary, Biscayne National Park, Dry Tortugas National Park, Buck Island Reef National Monument, Hol Chan Marine Reserve and Exuma Cays Land and Sea Park. Legislative measures such as these are of critical importance for safeguarding coral habitats, as they aim to reduce fishing pressures, prohibit trawling and dredging, limit tourism, and maintain clean, balanced ecosystems within which reefs can thrive.

Complimenting legislative measures are localised efforts to propagate, reintroduce and restore Acropora cervicornis within its endemic range, such as in Florida, Mexico, Puerto Rico, the Dominican Republic, Jamaica, and Honduras. Regions regularly affected by ship groundings and hurricanes have attempted to salvage damaged reefs by reattaching corals in Acrpoprid habitats, which accelerates the growth of new coral. In the Caribbean, what began as 60 Acropora restoration programmes in 2012, focusing primarily on asexual propagation or ‘coral gardening’ methods, has since grown significantly both in the number and size of programmes, now implementing larval propagation techniques in the interest of genetic diversity and adaptive capacity. In collaboration with scientists and restoration practitioners worldwide, the Coral Restoration Consortium (CRC) has developed a geo-referenced database to monitor data collected from restoration programmes across the globe, ensuring that coral conservation efforts are in sync and as effective as possible. In the Dominican Republic, the Dominican Consortium of Costal Restoration has implemented in situ nurseries, coral gardens, and sexual propagation programmes, primarily led by Fundación Dominicana de Estudios Marinos (FUNDEMAR) and Fundación Grupo Punta Cana (FGPC). In Bayahibe, novel advances in sexual propagation strategies have resulted in the seeding of hundreds of thousands of sexual recruits.

Due to the ever-growing threats of climate change, ocean acidification and disease, scientists have also shifted their focus towards more drastic interventions that aim at increasing the resistance of restored coral populations to thermal stress and disease. In Northwestern Australia, scientists have been studying a species of staghorn coral (Acropora aspera) that inhabit tidal areas and experience temperature swings of 7C as the tide goes in and out, enduring a maximum temperature of 32C. By studying the genetic profile of coral species that display an incredible resistance towards environmental stressors, researchers hope to transplant this coral globally to restore reefs in afflicted regions, or breed them with other species of coral to create offspring with better resistance to thermal stress. In addition to the genetic makeup of coral, another factor that appears to affect resilience to thermal stress and bleaching is the specific type of symbiotic bacteria that reside within the tissue of coral. As a result, scientists are attempting to apply topical probiotics that contain specific, beneficial strains of bacteria to protect coral species that are particularly susceptible to bleaching. 

You might also like: Exploring Costa Rica’s Trailblazing Efforts to Save Coral Reefs

An artificial propagation technique known as cyrofreezing, or cyropreservation, has also gained traction as a potentially important tool for conservation. Pioneered by researchers at the Smithsonian National Zoo, technology typically utilised for human sperm banks has been applied to the preservation of coral sperm and stem cells. By retaining genetic material that can remain viable for years, conservationists hope that frozen gametes can be used to breed new coral colonies in the future, restoring populations with low abundance and genetic diversity. Continued advancements in stem cell research further present the possibility of regenerating frozen stem cells into mature individuals. The sperm of Acropora cervicornis has been preserved within coral bio-repositories in the United States.

To further improve the efficiency and efficacy of conservation actions, continued research into Acropora cervicornis is of critical importance. Areas of research include: taxonomy; biology, behaviour and ecology; population; abundance and trends; habitat status; threats and resilience; restoration efforts; methods of identification; establishment and management of protected areas; recovery management; disease, pathogen and parasite management; and the success of current conservation strategies. In the US, the NOAA conducts research projects that track individuals to better comprehend population trends and causes of death, as well as testing the effects of temperature and acidification on eggs, sperm, larvae and newly settled colonies. With the continued collaboration of scientists and conservationists across the world, efforts to prevent the extinction of Acropora cervicornis have the potential to restore the species’ once immense abundance, cover, and occupied range.

How To Help

• Practice ethical tourism. When snorkelling or scuba diving, take care when wearing flippers or swimming near to coral reefs as coral branches may break easily when kicked or stepped on. Do not touch any marine life, as you may be carrying foreign bacteria, and do not take anything from the ocean (aside from rubbish).

• Use reef-friendly sunscreen. Next time you go swimming in the ocean, make sure to apply a “reef-safe” or “reef-friendly” sunscreen which does not contain any oxybenzone and octinoxate, as these are two common UV-blocking chemicals. When coral come into contact with such chemicals, symbiotic bacteria are unable to photosynthesise, and the coral suffers from bleaching.

• Donate your time with beach and ocean clean ups. Plastic pollution in oceans and along beach fronts is incredibly harmful to the health and vitality of coral reefs. Donate your time to beach and ocean clean ups in your local area, or volunteer abroad to discover the various species of coral across the world.

The axolotl (pronounced ACK-suh-LAH-tuhl) is a species of salamander under the genus Ambystoma (mole salamanders) that inhabits the lakes and wetlands of southern Mexico City. Unlike other amphibians, the axolotl is neotenic and does not go through metamorphosis, thus remaining aquatic and retaining its juvenile features into adulthood. A popular pick for the exotic pet trade, the ever-smiling, feathery-gilled axolotl is easily bred in captivity, having further piqued the interest of scientists and geneticists through its ability to regenerate parts of its body, such as its limbs, eyes, heart, spinal cord and parts of its brain. As such, the species’ plight is regarded as a conservation paradox: although abundant in captivity, rampant habitat degradation and disturbance has rendered the species critically endangered in the wild. 

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Appearance 

Axolotls are typically dark-coloured, with green or brown mottling and occasional silver highlights across their skin. Pink or light-coloured varieties are often bred in captivity for the pet trade, as these are regarded as more “pleasing” shades. Individuals can also shift their hue to a slightly lighter or darker colour if needed for camouflage. 

Measuring between 22 and 45 centimetres in length and weighing approximately 60 to 230 grams, the axolotl has a broad, flat body and a large head. Also referred to as the Mexican walking fish, individuals use their short, lizard-like limbs to carry themselves across the bottom of lakes and burrow into the substrate. Aided by webbed feet that operate like paddles, axolotls can move at an incredible 15 kilometres per hour when threatened. 

While most amphibians begin their life cycle in the water, gradually undergoing metamorphosis to develop the necessary features for a predominantly terrestrial adult life (such as air-breathing lungs and eyelids), the axolotl does not. In a phenomenon known as neoteny or paedomorphism, the axolotl forgoes metamorphosis and instead retains its juvenile features and aquatic habitat throughout its entire life cycle, reaching full size and sexual maturity. Although individuals do develop functional lungs and are able to breathe through their skin, the species uses external, feathery gills for underwater respiration. They also retain their tail, dorsal fin, and do not develop moveable eyelids.

Diet

Axolotls are carnivorous, nocturnal predators that employ an effective suction technique to inhale worms, mollusks, crustaceans, tadpoles, insects & their larvae, and small fish. Primarily targeting benthic organisms, the axolotl will often inhale gravel along with its prey, which aids with grinding and breaking down food within its stomach for digestion.

Habitat & Behaviour 

A close relative of the tiger salamander (Ambystoma tigrinum), the axolotl once occupied a number of high-altitude lakes and wetlands across the Mexican Central Valley, approximately 2,240 metres above sea level. Lakes Xochimilco and Chalco, two spring-fed lakes located on the southern edge of the Basin of Mexico, once served as primary habitat for the species, along with connecting lakes Texcoco and Zumpango. However, extensive drainage projects carried out in the region have resulted in a significant loss of suitable habitat for the axolotl. Today, the species occurs only in three sites – the canals of Lakes Xochimilco, Chalco, and Chapultepec – with an extent of occurrence of 467 square kilometres. 

The axolotl is a lentic species, inhabiting deep, still-water lakes. These amphibians require abundant aquatic vegetation for laying eggs, and are sensitive to shifts in water quality. During the day, individuals typically burrow into the sediment, in mud or among benthic flora to evade predators, such as storks, herons, and large fish (tilapia and carp), then hunt for prey nocturnally. Aside from a number of relatively simple insights, little is known about the ecology of wild axolotl populations, largely due to the fact that such populations are generally small and inaccessible. Existing information on the species has primarily been gathered from specimens kept in captivity, under laboratory conditions. 

With a life span of 10 to 15 years, axolotls reach sexual maturity between the age of six months to  one year. Following a dance-like courtship ritual, the male will deposit spermatophores onto the lake floor, which the female picks up with her cloaca to fertilise her eggs. The female will then lay an average of 300 eggs (although some can lay up to 1,000) on plants and rocks across the lake floor, obscured from predators. After approximately two weeks, the eggs hatch. Neither gender provide parental care, leaving larvae to fend for themselves.

Evolution and Adaptations

As mentioned, the axolotl has piqued the interest of scientists and geneticists for several of its ecological oddities; firstly, the fact that the species displays obligate neoteny. Some degree of neoteny occurs in 19 of the 32 extant species of Ambystoma, with most displaying facultative neoteny (a variation of metamorphosing and neotenic individuals or populations within the same species). Described as a developmental strategy, neoteny in salamanders has previously been linked to a lack of thyroxine (the hormone that primarily drives metamorphosis) during development, yet the ecological and environmental factors associated with its evolution are poorly understood. 

In April 2024, a study investigating several proposed factors favouring the evolution of neoteny in salamanders concluded that it was strongly associated with lower latitudes (the most southerly end of 20 to 30° N) and, to a lesser degree, higher elevations. This is presumably due to the reduced seasonality and increased stability of aquatic habitats at lower latitudes, where precipitation is higher and temperatures remain relatively constant.

For most metamorphic amphibians, changing seasons, shifting day lengths and rainfall patterns typically act as triggers for the start of development. Climatic stability at lower latitudes therefore emit weaker cues for the start of metamorphosis, which, combined with the stability of aquatic habitats, results in low pressure for energetically expensive morphological change across seasons. Although obligate neoteny limits the range of habitats that can be occupied, potentially imposing an ecological cost on the species, metamorphosis comes with a significant energetic burden to stimulate developmental changes. Therefore, if environmental elements and resources are sufficiently stable year-round, a salamander may benefit from forgoing metamorphosis and utilising that energy to reproduce earlier. Harsh terrestrial conditions, which are often associated with higher elevations, may further encourage the evolution of obligate neoteny where aquatic habitats are at lower risk of drying up. Rather than viewing neoteny as a constraint, the study posits that neoteny is an adaptive specialisation to stable aquatic habitats, which are found within a limited latitudinal range.

In some experiments, researchers have driven axolotls to undergo metamorphosis by forcing them to breathe air, retaining the amphibians in damp moss or reducing the quantity of shallow water available to them, as well as by feeding them a diet of mammalian thyroid. Although these specimens walked relatively well on land, developed skin as dry as a metamorphosed salamander (by shedding the larval skin), breathed air, and lost their external gills and fins – essentially demonstrating that the species is capable of undergoing metamorphosis – they were not able to survive as well as natural paedomorphic axolotls.

A second biological peculiarity that has confounded scientists is the axolotl’s ability to regenerate numerous parts of its body, such as its limbs, lungs, heart, jaw, spine, eyes, and sections of its brain. Studies have shown that the species can regrow a single limb five times in the span of a few weeks with no scars, replacing every layer of tissue: skin, bone, cartilage, muscle, and stem cells. Other organs can be regenerated numerous times while remaining fully functional. Naturally, researchers and geneticists have been eager to determine how the axolotl’s regenerative capabilities function and whether they can be applied to humans.

Despite the mammoth size of the axolotl’s genome (estimated to be approximately 32 billion base pairs), examinations of the axolotl’s biological development have been made significantly easier by the fact that they have large cells: their eggs are approximately 30 times larger than those of a human, and the neural plate cells of an axolotl embryo are almost 600 times greater by volume. Additionally, an axolotl’s pigmentation varies greatly with each cell, whereas cell traits are typically uniform in humans, making it easier for researchers to determine which tissues in an embryo develop into each organ. As a result, the axolotl played a pivotal role in understanding the development and function of organs in vertebrates, providing insights into the causes of spina bifida in humans, the discovery of thyroid hormones, and the way in which cells take on different forms in embryos. The axolotl has even proven capable of accepting transplanted organs and limbs from fellow axolotls without the risk of rejection, and is said to be 1,000 times more resistant to cancer than mammalian species. In 2011, an extract from axolotl oocytes (immature egg cells) was utilised to stop breast cancer cells from multiplying by activating a tumour-suppressor gene.

Yet, the mechanisms behind the species’ regeneration have yet to be identified. A number of scientists believe that obligate neoteny may enable axolotls to retain (or maintain active) a trait or gene from their embryonic stage that directs the growth of organs and limbs, since these genes are typically silenced in humans as adulthood is reached. Focusing on the blastema (the wounded end of a severed limb), researchers have observed that, while such wounds are typically covered with skin tissue in humans, axolotls transform proximate cells into stem cells and even recruit farther cells to move nearer to the injury. These cells then begin to form into bones, skin, cartilage, muscle, and veins, similarly to how an embryo develops, with transforming growth factor-β playing a key role in both axolotl regeneration and the prevention of scar tissue in human embryos during their first trimester. 

Ecological Importance 

Although the study of axolotl biology is of critical importance to medical, genetic and oncological fields, the species also plays a role of ecological importance within its native habitat. As a carnivorous predator, axolotls control the population of numerous small, benthic species, preventing any disruptions in the delicate balance of the ecosystem. These amphibians have also been described as an indicator species, due to their sensitivity to changes in water quality, temperature, and pollution levels. Declines in the population size or general health of wild axolotls can help scientists determine the degree of environmental degradation affecting lakes and wetlands across the Mexican Central Valley, which may then bolster conservation efforts in the region.

Threats

Although axolotl populations are relatively difficult to assess in the wild, surveys and studies conducted since 1998 have indicated significant declines across the species’ native habitat. In 2002 and 2004, over 1,800 nets were cast along Xochimilco canals covering 39,173 m², yet a mere 42 specimens were caught. Alarming drops in population density estimates have also been reported, from 6,000 ind/km² in 1998, to 1,000 ind/km² in 2004, to 100 ind/km² in 2008, to 35 ind/km² in 2017. Ecological niche modelling has indicated that the axolotl’s potential distribution within Xochimilco is limited to 11 reduced, scattered, and isolated sites in areas dominated by agriculture, and monthly sampling in the region has failed to record the species since 2017. Density studies have not been conducted for Lake Chalco subpopulations, as the site is regarded as highly unstable and at risk of disappearing in the near future. The only site where observations of the species have been recorded in the last six years is Chapultepec Lake: an artificial, cement-lined lake within a city park. As such, the axolotl is estimated to have suffered a population loss of at least 80% over the past three generations, classifying the species as Critically Endangered under the IUCN Red List.

Axolotls primarily inhabit two freshwater lakes within one of the largest, most densely populated cities in the world: Mexico City. When the Aztecs first arrived in the Valley of Mexico in 1325 C.E, the region consisted of five interconnecting lakes, the biggest of which was Lake Texcoco. Building their empire, the city of Tenochtitlan, on two islands near the western edge of Lake Texcoco, the Aztecs extended the region by braiding reeds and stakes to form small, stationary, floating islands (chinampas, or “floating gardens”) used primarily for agriculture. In total, Tenochtitlan encompassed an area of approximately 14 square kilometres. Although the Aztecs were known to consume axolotls as part of their diet, the abundance of suitable habitat and low-impact agriculture meant that the species thrived at the time.

In 1607, Spanish conquistadors sought to expand Tenochtitlan beyond its borders into the lakebed of Lake Texcoco. The city was destroyed and a Desagüe was built to drain the Valley of Mexico of its system of lakes. Flooding caused by heavy rainstorms further fuelled drainage projects, and Mexico City was built upon the ruins of Tenochtitlan, with most of the new city resting in the basin of Lake Texcoco. Today, there remain only vestiges of Lakes Xochimilco, Chalco, and Zumpango. Most of the water remaining in the canals of Xochimilco emanates from a water treatment plant and is heavily polluted due to infrastructural development, agricultural run-off, tourism, and inadequate waste management practices. When Mexico City’s antiquated sewer system is flooded after heavy rainstorms, treatment facilities will release human waste into Xochimilco, flushing canals with ammonia, heavy metals, bacteria, and toxic chemicals. Since amphibians, such as the axolotl, have highly permeable skin through which they sometimes breathe, this frequent exposure to pollution makes them extremely vulnerable to disease and poisoning. Further exacerbating the axolotl’s plight, several years of low rainfall, long periods of drought, and increasing temperatures brought about by climate change have made remaining natural habitats susceptible to drying up.

Another primary threat to wild axolotl populations has been the introduction of invasive species to the lakes and canals of Mexico City. In the 1970s and 1980s, the Mexican government, in collaboration with the Food and Agriculture Organisation of the United Nations, released thousands of common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) into Xochimilco as part of a national poverty relief project. Since these two species were easier to breed, it was believed that the initiative would feed a greater volume of people and incorporate more protein into local diets. Unfortunately, the carp and tilapia quickly assumed the position of top predators, consuming axolotl eggs and juveniles, as well as the main prey sources of adult axolotls. Today, these introduced fishes have multiplied to extremely high abundances, with tilapias comprising 95% of the canals’ animal mass. In a recent study, researchers collected approximately 600 kilograms of tilapia in one small channel utilising a 100 metre net.

Although wild axolotls were previously caught for the international pet trade, for local consumption, and for medicinal uses, it is now presumed that any axolotls traded nationally or internationally are bred in captivity. Nevertheless, scientists have recently expressed concern about the degree of inbreeding observed in laboratory specimens, should wild axolotls go extinct. This lack of genetic diversity is partly due to the fact that the heritage of most laboratory axolotls can be traced back to a group of 34 individuals captured in Xochimilco in 1863 by a French-funded expedition, which marked the start of widespread axolotl breeding across Europe by naturalists and museums. 

Despite attempts to introduce wild axolotls to captive populations to diversify the gene pool, and even attempts to add tiger salamanders (Ambystoma tigrinum) to the mix, scientists have calculated an average axolotl inbreeding coefficient of 35% (a score over 12% indicates breeding with first cousins and is of serious concern). Therefore, most axolotls in laboratories and aquariums across the world are not only highly inbred, but are also part tiger salamander. Significantly more vulnerable to infectious disease, malformations, and genetic abnormalities, which have already been observed within axolotl breeding programmes, these inbred captive populations are unsuitable for reintroduction and repopulation efforts. Furthermore, scientists cannot be certain that specimens being studied have not already diverged from their wild counterparts to the extent that they have lost pivotal elements of regeneration. 

Conservation 

In 2021, the axolotl was launched into pop culture fame after being featured in the popular video game, Minecraft, with its feathery gills and winning smile keeping the amphibian in the limelight. However, the species’ plight has not yet garnered the same widespread awareness, potentially due to its abundance in captivity. At present, the axolotl is protected under category P (“Peligro de Extincion”, or Risk of Extinction) by the Government of Mexico, and although the species is listed under Appendix II of the Convention on International Trade in Endangered Species (CITES), it is under the process of “Periodic Review of species included in CITES Appendices”. In 1987, the Xochimilco wetlands were nominated a UNESCO World Heritage Site, and in 1992 the whole lake system was designated a protected area. Regardless of these legislative measures, which have done little to halt drastic axolotl population declines, officials have yet to design and implement effective, long-term, holistic conservation strategies that target the species’ two greatest threats: habitat degradation and invasive species. 

One ongoing project that has been attempting to restore the axolotl’s freshwater habitat is Refugio Chinampa led by Luis Zambrano, a systems biologist at the National Autonomous University of Mexico. The project aims to restore the Aztec agricultural practice of chinampas (“floating gardens”) by working with chinamperos (farmers with plots of agricultural land in the Xochimilco lake system) to build natural canals separate from Xochimilco’s main waterways, effectively protecting axolotls from introduced predators and pollution. As mentioned, chinampas are floating structures in waterways built from reeds, sticks, earth, and other natural materials, and were previously used for sustainable agriculture. These structures contribute to the protection of native species, serving as a refuge for axolotls from predators such as carp and tilapia, and act as bio-filters that clean the water of Xochimilco’s canals and trap carbon dioxide. Local farmers who are willing to participate in the project, such as Felipe Barrero, have donated parts of their land to the cause, have agreed to dig new canals, and have committed to stop using pesticides. The practice of chinampas may also increase the availability of jobs in the region, boost the production of agricultural produce, and encourage ecotourism in the region.

Although it has been difficult for the project to source chinamperos willing to collaborate, largely due to the fact that pesticides and chemicals have been widely promoted as efficient resources for growing vegetables, those involved with the project believe that change is emanating from younger generations of chinamperos. By following the environmentally conscious farming practices of the Aztecs, and with education and awareness campaigns increasingly inspiring students and young adults to have an interest in ecology, improvements in the water quality of Xochimilco will allow native species, such as the axolotl and its prey sources, to thrive in the region once again. It can take over one year to condition a canal for the reintroduction of axolotls, as the process involves building a precise micro-ecosystem from the ground up, taking into account details such as flora and fauna. Once the canal is deemed habitable and safe, releases from captive populations can be considered.

The issue of invasive species is slightly more complicated, as populations of both carp and tilapia have exploded in the past decades. One solution, proposed by Zambrano, is to map out regions of Xochimilco where axolotl populations persist and hire teams of local fishermen to sweep these areas of fish on a regular, long-term basis. While this practice would not remove all the fish, these sweeps would reduce the pressure on axolotls for a window of time within which the species could re-establish itself. Since tilapia have been found to target axolotls at the juvenile stage, and carp tend to feed on axolotl eggs, Zambrano believes that axolotls might be able to thrive if the risk of predation were lessened while at their most vulnerable life stages. 

The possibility of using lab-bred axolotls to repopulate Xochimilco and surrounding lake systems has been studied with promising results. In 2013, the Centre for Biological and Aquaculture Research (CIBAC), a breeding facility near Xochimilco, released several thousand axolotls for a behavioural study, with some surviving and breeding in the following year. CIBAC is attempting to breed wild-type axolotls in an effort to preserve the species’ genetic diversity, and notes that captive-bred salamanders may thrive in the wild if raised to be a certain size before their release. In 2017, Zambrano released 10 lab-bred wild-type axolotls into a protected pond near the National Autonomous University of Mexico campus, with the hope that these individuals, should they survive and breed, might act as a genetic bank for the species in the future. In the span of two years, Zambrano periodically released and tracked axolotls to better understand their behaviour and preferred habitat. His research indicates that the species prefers relatively dirty ponds over pristine ones, which means that Xochimilco could serve as a suitable habitat once other pressures are mitigated.

Scientists and conservationists have stressed the importance of neutralising the threats of predation and pollution before attempting the reintroduction and repopulation of axolotls in Xochimilco, as premature releases could potentially provoke an increase in invasive fish numbers if axolotls were simply offered as an easy prey source. Examples of successful reintroductions, such as the pool frog (Pelophylax lessonae) in Britain and the hellbender salamander (Cryptobranchus alleganiensis) in the United States, have involved careful management of the focal ecosystem and the cooperation of surrounding communities.

If you want to learn more about endangered species, make sure to check out other articles from our Endangered Species Spotlight Series

How To Help

• Use natural products in your home. Even if you do not live in Mexico City, products that contain ammonia or heavy metals are incredibly harmful for any ecosystem or environment around the world. When purchasing cleaning or personal hygiene products, try to look for organic, plant-based or natural items that are free of heavy chemicals. Products like wet wipes, detergents containing phosphates, micro-beads in toothpastes, face washes, scrubs and abrasive cleaners, chlorine-based bleach and aerosol cans are some to avoid.

• Raise Awareness. The axolotl may be widespread in fish tanks and laboratories across the world, but its wild population faces a high risk of extinction. Let your friends and family know about the plight of the axolotl, raise awareness in your local community, and educate others about the importance of saving this incredible species.

• Get involved. If you are keen to get involved with the conservation of the axolotl and its native habitat, you can host a fundraiser, get involved with a conservation organisation to volunteer your time in Mexico City, or donate to research and conservation efforts.

Featured image: John P Clare/Flickr.

Easily recognised by its resplendent yellow crest and gold-tinted blush – or perhaps more so by its raucous squawk – the yellow-crested cockatoo is one of 21 species of cockatoo (family Cacatuidae) in the order Psittaciformes (parrots). Although endemic to Timor-Leste and Indonesia, where populations were previously found throughout Nusa Tenggara, on Sulawesi and its satellite islands, and on the Masalembu Islands, the species has suffered rapid population declines due to rampant trapping for the exotic pet trade. Having been driven to extinction in a substantial portion of its former range, the yellow-crested cockatoo is currently classified as critically endangered. Incredibly, feral populations of several hundred birds exist in the highly urbanised cities of Hong Kong and Singapore, as well as in China, which could potentially play a significant role in the recovery of the species worldwide. However, for such conservation efforts to succeed in the long term, primary threats such as poaching and habitat loss must first be eliminated in the endemic range of the species.

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1. Appearance

The yellow-crested cockatoo, also known as the Lesser Sulphur-crested cockatoo, is a medium-sized species measuring approximately 33 to 35 centimetres in length when fully matured. It is often confused with the larger and more common Sulphur-crested cockatoo (Cacatua galerita), which is found in Australasia and is distinguishable by the absence of yellow patches beneath its eyes. Although subspecies of the yellow-crested cockatoo are generally regarded as synonymous, apart from the notably larger Cacatua sulphur abbotti, recent studies have uncovered significant morphological differences between the birds, as well as possible subspecific division within Cacatua sulphur djampeana. The citron-crested cockatoo (Cacatua citrinocristata) was previously recognised as a subspecies of C. sulphur but was subsequently regarded as a separate species, given its orange hue.

The adjustable, forward-curling feather crest of a yellow-crested cockatoo is a magnificent shade of yellow, flaring up as a form of both intraspecific and interspecific communication when the bird is alarmed, excited, aroused or threatened. It is also theorised that the crest makes cockatoos appear larger to potential predators, serving as a defence mechanism. The two patches of yellow feathers beneath the eyes of yellow-crested cockatoos are ear-coverts – patches of feathers that cover the bird’s ear openings, since the ear of a bird has no external features. The species also has a yellow wash on the underside of its wings.

Like other cockatoos, the yellow-crested cockatoo has a stout, curved bill. This curved beak shape lends greater holding power than a straight beak would, allowing the bird to crack nuts and hard seeds, prune leaves, scoop fruit pulp, scrape the bark off trees, and dig up earth. All members of the Psittaciformes order also share zygodactyl feet, where the first and fourth digits face backwards while the second and third digits face forwards, providing these birds with an incredibly strong grip and excellent climbing abilities. Short tails further confer the speed and agility necessary to navigate dense forests.

Cockatoos are typically less colourful than other members of the parrot order, with most species under the genus Cacatua sporting all-white plumage. This is primarily caused by the lack of Dyck texture in their feathers, which typically produces blue and green colours in the plumage of other parrot species by the way in which it reflects light. 

2. Diet

On the small Indonesian island of Masakabing, research has shown that yellow-crested cockatoos preferentially consume breadfruit (Artocarpus communis, a species of flowering tree in the mulberry and jackfruit family), the fruit and flowers of coconut palms (Cocos nucifera), young leaves and flowers from kapok trees (Ceiba petandra) and mangroves, as well as the seeds, flowers and fruit of at least six other species of flora. More generally, the diet of the species consists of seeds, nuts, roots, fruit, leaf buds, shoots, and flowers, depending on the season and geographic location of the bird. Its zygodactyl feet, muscular tongue and strong, curved beak allow the yellow-crested cockatoo to crack hard nuts, de-husk seeds, and manipulate its food with relative ease.

3. Habitat & Behaviour

Endemic to Timor-Leste and Indonesia, the yellow-crested cockatoo was once found throughout Nusa Tenggara, Sulawesi, and the remote Masalembu Islands in the Java Sea. After decades of drastic declines due to trapping and habitat loss, small populations are now confined to the South-east Sulawesi province, one island in Central Sulawesi, and three satellite islands to the south. Notable populations continue to occur on West Timor and Timor-Leste, as well as the Flores Sea and Sumbawa island groups, including a group of approximately 1,000 individuals on Komodo Island. The species has been extirpated from several islands in the Lesser Sundas, Masalembu Island, and Lombok. With only 17 to 22 individuals remaining in the wild, the subspecies Cacatua sulphur abbotti is among the rarest and most threatened cockatoos, found only on Masakambing Island in the Masalembu Archipelago. A feral population of several hundred birds can be found in Hong Kong, China and Singapore, with these birds displaying an incredible ability to survive outside their natural range and preferred habitat.

Yellow-crested cockatoos typically inhabit evergreen, moist deciduous, monsoon and semi-evergreen forests, forest edges, scrubland, and agricultural land. The species can be found at altitudes of up to 500 metres on Sulawesi, and between 800 and 1500 metres in Nusa Tenggara. Although previously believed to require closed-canopy primary forest to thrive, populations in Sulawesi have been observed inhabiting forest savanna and open habitats rather than primary forest. As mentioned, drastic adaptations are also seen in the feral cockatoo populations of Hong Kong and Singapore, where these birds have survived as an introduced species in highly urbanised environments with limited forest coverage.

Females nest in tree cavities with specific requirements, typically opting for a pre-existing nest hole or chink in the trunk of a dead, snagged or rotting tree that is optimally over 100 years old. Nomadic by nature, cockatoos travel in groups or flocks to areas where food stocks are abundant, flying and foraging diurnally before returning to their home roosts for the evening.

In addition to the feather crest, vocalisations are used extensively by cockatoos for intraspecific communication. From single harsh screeches and loud, raucous calls, to sweeter whistles and squeaky notes, these vocalisations may serve as a form of individual identification within flocks, as well as to warn others of a potential threat or danger, to express emotion, to stay together, and to protect their nests. Loud calls are a particularly useful adaptation for cockatoos who live in thick, dense forests, as birds in a flock can communicate over long distances without the need to locate each other.

Members of the Psittaciformes order, together with those in the family Corvidae, are considered to be the most intelligent of birds. This is due to the fact that these species have a brain-to-body size ratio equivalent to higher primates. Early childhood learning appears to be of critical importance to cockatoos and is primarily social in nature. Playing, predator avoidance, and foraging are important aspects of learning, ordinarily taught by siblings, flock members and parents. Insufficient stimulation may result in young birds developing destructive behaviour, which often occurs when these species are kept as pets.

4. Ecological Importance

Although researchers have yet to fully understand the specific role that yellow-crested cockatoos play in their native ecosystem, the herbivorous diet and nomadic nature of the species indicates that it plays a part in seed dispersal and the distribution of plants. The yellow-crested cockatoo further occupies a place in the food chain, with its eggs and chicks serving as prey for Komodo dragons (Varanus komodoensis), as well as two birds of prey: the spotted kestrel (Falco moluccensis), and the white-bellied sea eagle (Haliaeetus leucogaster). Komodo dragons and yellow-crested cockatoos also compete for nesting space on Sterculia foetida trees, with Komodo dragons often invading the nests of yellow-crested cockatoos during their arboreal phase.

5. Threats

Following intensive surveys conducted between 2016 and 2019 across Indonesia and Timor-Leste, researchers determined that the total population of yellow-crested cockatoos left in the wild numbered approximately 1,800 to 3,140 individuals, or 1,200 to 2,000 mature individuals. Despite limited data on the species’ population size prior to 1980, the sheer extent of the commercial trade in yellow-crested cockatoos in the 1980s and 1990s, fuelled by an intense and inexplicable demand for the mischievous bird as a pet, has led conservationists to suspect that the once widespread species has suffered population declines of 80-90% over the past three generations. As a result, the yellow-crested cockatoo has been classified as ‘Critically Endangered’ under the International Union for Conservation of Nature (IUCN) Red List. Although future declines are predicted to occur at a much slower rate, given that the majority of remaining populations are concentrated in protected areas, the threat of trapping, as well as the growing threat of deforestation, continue to pose a significant risk of extinction to small, isolated populations. 

In the last quarter of the 20th century, demand for yellow-crested cockatoos as pets soared internationally, creating a financial incentive for the trapping and sale of wild birds. Throughout the 1980s, between 5,200 and 12,000 yellow-crested cockatoos (figures include C. citrinocristata as a subspecies) were imported to Singapore annually, and an estimated 96,000 individuals were exported from Indonesia between 1981 and 1992. Although trapping the species became illegal in Indonesia in 1990 under the Conservation Act, and while trapping rates have decreased from historic levels in the 1980s, the commercial trade of yellow-crested cockatoos has continued domestically and internationally due to poor enforcement and monitoring. This is particularly true of the smaller Indonesian islands of Rote, Alor, and Pantar, where capacity for the enforcement of regulations prohibiting hunting and trade is limited. In 2015, Indonesian authorities seized a suitcase containing 23 yellow-crested cockatoos and one green parrot that had been stuffed into plastic water bottles. The alleged wildlife smuggler was apprehended at Surabaya Port, Java, where officials typically search every ship for illicit smuggling activity despite limited manpower. Given the discretion to impose fines of up to 100 million rupiah (US$6,800) and prison sentences of up to five years on those convicted of trapping a protected species under the 1990 Act, some claim that courts rarely impose fines greater than 10 million rupiah (US$690) or sentences greater than 18 months. Such penalties amount to a mere fraction of the income that poachers receive for the sale of wild cockatoos, which, coupled with inadequate monitoring and apprehension by law enforcement, leaves them with little reason to fear retribution. 

In 2005, the yellow-crested cockatoo was listed under Appendix I of the Convention on International Trade in Endangered Species (CITES), thereby banning the commercial trade of the species.

Nevertheless, due to a legislative grey area, cockatoos can still be traded legally if they originate from a captive breeding facility, rather than having been caught in the wild. The issue with such a caveat is that identifying the difference between wild-caught birds and captive-bred birds is incredibly difficult in practice. Although some countries have methods for distinguishing the two, such as in Hong Kong where captive-bred cockatoos must be tagged with a leg band and ID number, monitoring and enforcement practices are often inadequate. According to Astrid Andersson, a postdoctoral researcher at Hong Kong University who specialises in cockatoos, surveys of Hong Kong’s Yuen Po Street Bird Market revealed that some birds were not wearing a band, or had one that could be removed or that did not display an ID number. In a visit conducted by CNN to the same bird market in May 2023, yellow-crested cockatoos spotted on display were said to be pets. However, after expressing interest in purchasing a cockatoo, shopkeepers claimed to be able to source a yellow-crested cockatoo for HK$28,000.

While the Hong Kong Government’s Agricultural, Fisheries and Conservation Department (AFCD) has stated that the last commercial import of yellow-crested cockatoos occurred in 2004, and that there are no CITES-registered breeding operations in the city, there remains the possibility that home-breeding occurs amongst private pet owners. In recent years, Facebook has become a popular platform for the trade of exotic pets, such as cockatoos, as the practice is slightly more covert. WWF Hong Kong tend to monitor online groups for the trade of protected birds, often observing young chicks being sold. The organisation has noted that traders typically require buyers to send private messages, or utilise cryptic keywords to disclose the price of the bird, such as its flying distance. 

Since the 1980s, conservationists have largely regarded trapping as posing the greatest threat of extinction to wild yellow-crested cockatoo populations across Indonesia and Timor-Leste. However, as remaining populations are now largely concentrated in protected areas and legislative measures have rendered commercial trade more difficult, a new and growing threat has come to light: deforestation. Extensive logging and the conversion of primary forest to agricultural land has affected the diversity of flora found across the species’ native ecosystems, altering the availability of food sources and exposing cockatoos to a greater risk of predation and poaching. Based on studies conducted by the Global Forest Watch in 2021, which estimated the mean annual rate of forest cover loss over the previous five years, researchers have projected a forest loss rate of approximately 16.1% across the current occupied and probably occupied range of yellow-crested cockatoos over the next three generations. Although the yellow-crested cockatoo has proven adaptable to land conversion and varied habitats, the the species’ dependence on large, old trees with substantial hollows for nesting, typically found in old growth forest, has led researchers to estimate population declines of 30 to 49% over the next three generations.

For Flores Sea island cockatoo populations, agricultural conversion is currently considered to be a primary threat, while poaching for local consumption, rather than for the pet trade, has been identified as a secondary threat. On Komodo Island, juvenile Komodo dragons compete with cockatoo chicks for nesting sites, with deforestation and loss of forest cover further exposing nestlings to predation by large birds of prey. Studies on the citron-crested cockatoo (C. citrinocristata) have identified competition with fellow parrots and owls for nesting sites in large, hollow trees, primarily in areas targeted by logging, as a primary cause of low productivity. Given the similarities in ecology between citron-crested and yellow-crested cockatoos, some have speculated that such competition may also affect the productivity of the latter species. Yellow-crested cockatoos have also been observed raiding agricultural plots, consuming ripened crops or digging up newly sown seeds, as natural food sources become increasingly scarce. As a result, some communities view cockatoos as pests, not only exposing the birds to conflict or retaliatory acts, but also reducing local support for their conservation. 

Discover more on Earth.Org’s Endangered Species Spotlight Series

6. Conservation

In addition to listing the yellow-crested cockatoo under Appendix I of CITES in 2005, a cooperative recovery plan was implemented by signatories, and the species’ recovery was declared a national priority by the Ministry of Forestry and Environment of Indonesia. Although governmental conservation efforts have largely been limited to legal protections, the establishment of protected areas and national parks with intensive safeguarding measures have had some success. On Sulawesi, the removal of overhanging vegetation and the installation of plastic collars around the trunks of nesting trees have reduced the threat of predation for cockatoo nestlings. In Komodo National Park, the yellow-crested cockatoo population of over 1,100 individuals, arguably the most important population at present for recovery efforts, is currently stable and well-protected. In some regions, mangrove restoration projects are also underway in an effort to improve the availability of nesting habitats for cockatoos.

Given the implementation of legislative regulations limiting international trade in yellow-crested cockatoos, domestic trade likely accounts for a large proportion of the current market. Organisations such as the World Parrot Trust have therefore promoted community engagement programmes and local education initiatives to reduce trapping and foster conservation. These projects have included providing communities with binoculars and field guides to encourage parrot watching, as well as suggesting ecotourism projects, such as locally-guided birding trips.

In 2008 and 2009, surveys conducted by the Indonesian Parrot Project led to meetings with community leaders, villagers, police and local military on the islands of Masakambing and Masalembu in an attempt to raise awareness about the plight of yellow-crested cockatoos, shed light on the species’ ecological importance, and encourage engagement in its conservation. Schools across the Masalembu Archipelago and in south-east Sulawesi have embraced Conservation Awareness Pride programmes, engaging both adults and children in understanding the importance of protecting local ecosystems and endangered species. Additionally, a ‘village regulation’ was implemented to prohibit the trapping, ownership or transportation of yellow-crested cockatoos, and to initiate measures to reduce habitat disturbance. By employing a former village head to enforce the regulation, monitor nests and study the species, this locally-mediated policy has enabled the local population of yellow-crested cockatoos to increase by nearly threefold over a period of 12 years. Similar community-led initiatives have been implemented in the Moronone community of Sulawesi, where four Forest Wardens are tasked with monitoring the species and prevent trapping. To reduce conflict between farmers and cockatoos, it has been suggested that additional or ‘sacrifice’ crops could be planted to compensate for losses, such as sunflower fields which typically attract the attention of cockatoos away from other crops.

In Hong Kong, where the international trade of yellow-crested cockatoos has proven to have remained active, efforts are underway to create unique strategies for reducing the illegal trade. Astrid Andersson, a postdoctoral researcher at the University of Hong Kong’s conservation forensics laboratory, has developed a forensic tool that could help distinguish between captive-bred and wild-caught cockatoos in Hong Kong. Wild cockatoos consume a wide variety of seeds, leaves, shoots, flowers and fruits, whereas captive cockatoos tend to receive a diet high in corn, which has a distinctive carbon ratio. By using a “stable isotope analysis” to examine the carbon and nitrogen in the feathers of any given cockatoo – a test which is inexpensive and takes only one week to yield results – authorities could potentially determine whether cockatoos sold at pet markets were recently taken from the wild. 

Now, Andersson has focused her efforts on the genetic analysis of Hong Kong’s yellow-crested cockatoo population to determine their origins. By extracting tissue samples from local birds and comparing their DNA with that of museum samples from the species’ natural range, Andersson hopes to determine whether Hong Kong’s cockatoos are inbred, hybrids, or pure subspecies from a specific region in Indonesia. The analysis could further shed light on the age and genetic health of the local population. While this information could help with understanding Hong Kong’s yellow-crested cockatoos, potentially providing insights into the species’ ecology in general, the analysis could also indicate whether the city’s population could assist with genetic rescue in Indonesian populations should it be needed.

While conservation initiatives implemented thus far have had success in safeguarding yellow-crested cockatoo populations remaining in the wild, as well as in garnering public interest in their protection, the IUCN has noted further conservation and research actions that have been proposed for the species. These include: strengthening law enforcement in protected areas and monitoring trade in key locations; promoting widespread community-based conservation initiatives, particularly on small islands; monitoring population trends and identifying critical areas for protection; maintaining regular patrols, raising awareness in local communities, and studying the impact of human activities on the species within Komodo National Park; conducting further ecological research to develop better strategies for the species’ management and conservation; studying the abundance of nest holes and water sources; and monitoring forest loss within the species’ range.

NGO Spotlight: Indonesian Parrot Project

Founded in 2001, the Indonesian Parrot Project (IPP) is dedicated to conserving Indonesian cockatoos and parrots through projects both in the field and across local communities. In 2004, after a smuggler was apprehended on Seram Island with a number of parrots and cockatoos, a collaboration between the National Park of Manuela and the IPP resulted in the establishment of the Kembali Bebas Avian Rescue, Rehabilitation and Release Centre. With the support of private donors and grant money, the IPP expanded the facility to include 60 cages and an on-site avian medical clinic, receiving birds seized from smugglers and preparing them for release. In 2008, the project was turned over to the local community, with continued involvement from the IPP to locate funding, and the facility continues to improve its resources for the care and eventual release of trapped birds. 

As mentioned, the IPP also designed and implemented a Conservation Awareness Pride (CAP) Programme, designed to educate children about cockatoos and parrots across Indonesia, their importance to the ecosystem, and to foster a genuine interest and passion for conservation in young generations. By raising awareness on the inhumane effects of trapping, the exotic bird trade, and the lasting effect that population declines can have on the environment, as well as highlighting how incredible cockatoos are as a species, the CAP programme aims to instil a sense of pride in local communities and garner a strong desire to protect their surrounding environment. The programme includes: cockatoo colouring books, t-shirts and posters; murals; city signs; drawing contests; songs; TV and radio presentations; and trips to the Kembali Bebas Rehabilitation Centre to witness the release of birds.

The IPP has also facilitated a participatory process to introduce and establish small business opportunities that address the needs of local communities and operate on their values, traditions, and customs. By providing training, mentoring, services, and motivation to locals who may otherwise rely on the trapping of wild birds to secure an income, communities are able to build sustainable sources of income for themselves with the support of the IPP, achieving financial self-reliance while promoting ecologically friendly economic development. Some alternate avenues of sustainable income introduced by the IPP include: hiring forest wardens to monitor and protect nests; supporting businesses led by local women, such as arts, crafts, and organic farming; and hiring local guides for ecotourism projects.

The IPP also conducts scientific studies on Indonesian cockatoos and parrots, such as genetic analyses, censuses, breeding analyses, and studies on their nesting behaviours and food requirements, to better understand the ecological needs of these species. Such data not only helps with the care of birds in rehabilitation, but also supports the design of data-driven, efficient conservation actions. Lastly, in collaboration with both governmental and non-governmental agencies, the IPP monitors the illegal trade of cockatoos in an attempt to reduce trapping and smuggling. 

Among the most admired species in the animal kingdom is the majestic tiger, the largest wild cat in the world. Easily recognised by its uniquely striped, reddish-orange coat, the tiger is an apex predator across its endemic range states and holds cultural significance at national and local levels. Despite this widespread reverence, tiger populations have been declining for decades primarily due to anthropogenic threats, such as poaching, habitat loss, and the depletion of prey stocks. While conservation efforts for flagship species are typically well funded and tend to garner widespread public attention, the implementation of multifaceted, evidence-based conservation measures that adequately reflect the needs of both the target species and of local communities is a complex, lengthy process. 

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1. Taxonomy

The evolutionary history and genetic diversity of tigers is a topic that still remains relatively understudied. Since 2004, the intraspecific taxonomy of Panthera tigris has been the subject of debate due to conflicting results from different methodologies.

Luo et al. (2004) utilised the analysis of mitochondrial DNA to identify six subspecies, whilst Wilting et al. (2015) identified just two subspecies based on morphological (craniodental and pelage), ecological and molecular traits. However, these inconsistencies were partly attributed to an insufficiency of genetic samples across the range of the species. Liu et al. (2018) subsequently employed whole-genome sequencing analyses on 32 voucher specimens, which resolved six statistically robust monophyletic clades corresponding to extant subspecies with little admixture and gene flow between them. Nevertheless, due to the varied data results, the taxonomy of Panthera tigris remained under review by the International Union for Conservation of Nature’s Species Survival Commission (IUCN SSC) Cat Specialist Group. 

The six extant subspecies identified by Liu and his team in 2018 were: the Amur tiger (P. t. altaica); the Northern Indochinese tiger (P. t. corbetti); the Malayan tiger (P. t. jacksoni); the Sumatran tiger (P. t. sumatrae); the Bengal tiger (P. t. tigris); and the South China tiger (P. t. amoyensis), although this subspecies is considered to be extinct in the wild. Three extinct subspecies were also recognised based on morphological traits: the Bali tiger (P. t. balica); Javan tiger (P. t. sondaica); and the Caspian tiger (P. t. virgata).

The two subspecies identified by Wilting and his team in 2015 were: Continental tigers (Panthera tigris tigris), under which virgata, altaica, amoyensis, corbetti and jacksoni were subsumed, and Sunda Island tigers (Panthera tigris sondaica), which included balica and sumatrae.

Most recently, Armstrong et al. (2021) re-sequenced 65 individual tiger genomes derived from the most extant subspecies, with a focus on tigers within India (where 70% of the world’s wild tigers are found). The study revealed genome-wide signatures of phylogeographic partitioning and evidence for long-term restriction of gene flow and adaptive divergence. These results therefore reinforced earlier analyses suggesting significant genetic differentiation between six putative tiger subspecies, despite a relatively recent divergence of 20,000 years between tiger populations. Authors noted that such swift genetic differentiation highlights the role of genetic drift or stochastic processes, as well as intense population bottlenecks, in recent tiger evolution. 

Intraspecific taxonomy and a comprehensive understanding of a species’ natural history from a genomic perspective is of critical importance to conservation planning, as it provides the foundation for the implementation of data-driven, evidence-based measures. By recognising the genetic diversity, evolutionary uniqueness, and potential of different tiger populations, conservation strategies can better reflect the specific biological and ecological needs of each subspecies, particularly the rarest and most endangered populations. 

You might also like: 10 of the World’s Most Endangered Animals

2. Appearance

The majestic tiger has a striking, reddish-orange coat with pronounced black stripes, white fur on its ventral side, and a single white spot behind each ear. A tigress will use these white spots to communicate with her offspring by flattening her ears upon sensing danger, prompting her cubs to hide. The black stripe pattern of a tiger is unique to each individual, similarly to human fingerprints, allowing researchers to identify different specimens in the wild.

Due to genetic factors, some variation in pelage colouration does occur in tigers, particularly within India. In 2007, ‘black’ or ‘pseudo-melanistic’ tigers were officially discovered in Similipal Tiger Reserve, Odisha; the only wild population to currently exhibit this trait. Due to an extremely rare genetic mutation, these tigers have thicker, darker stripes that merge together, thus appearing to be almost black in colour. Despite the rarity of this mutation, approximately 37% of tigers in the Similipal Tiger Reserve are pseudo-melanistic. In a 2021 study on the ongoing phenotypic evolution of pseudo-melanism in tigers, Sagar et. al. (2021) highlighted the possibility of inbreeding and population bottlenecks within the small, isolated population of Similipal. 

White tigers were first observed among wild Bengal tiger populations in India, and exhibit white fur and sepia brown stripes due to an autosomal recessive trait. Golden tigers have pale-golden fur and reddish-brown stripes, also due to an autosomal recessive trait. The rarest variant, caused by a polygenic trait determined by dual-recessive effects, is the snow white tiger, which is almost completely white with faint or near non-existent stripes on its body and light sepia brown rings on its tail.

When hunting, tigers typically deliver a rapid but fatal bite to the throat of their prey. These fierce predators therefore have razor-sharp canines that can reach up to 10 centimetres in length, strong jaws with a bite force of 1,050 psi (whereas a human has a bite force of around 160 psi), and incredibly agile bodies.

The Amur tiger is the largest subspecies of tiger, as well as the largest wild cat, with males measuring up to three metres and weighing up to 300 kilograms. The Sumatran tiger is the smallest subspecies, reaching a maximum weight of 140 kilograms and measuring 2.4 metres. All subspecies appear to display slight sexual dimorphism, with females tending to be smaller than males. 

3. Diet

Tigers are solitary, ambush predators, hunting prey with an incredible display of stealth, speed, agility and strength. Camouflaged by its striped coat, a tiger will lie in wait or actively search for prey and pounce once the opportune moment arises, aiming for the animal’s neck. Since the species primarily hunts at night, prey is identified through sight and sound. To enhance their nocturnal vision, tigers have an additional layer of reflective tissue in the back of their eyes called the tapetum lucidum. Located behind the retina, this layer of tissue reflects light that enters the pupil so that it hits the light-detecting cells of the eye twice, improving the vision of the tiger.

Tigers are also skilled swimmers and have been observed hunting in water. 

As apex predators and obligate carnivores, tigers primarily consume large ungulates such as wild pigs and deer of various species. These powerful cats are capable of taking down ungulate prey much larger than themselves, such as water buffalo, gaur, banteng, and even Asian elephants and rhinoceros. Yet, similarly to most large carnivores that display optimal feeding behaviours, tigers will prefer prey of a similar weight to themselves. A tiger is typically successful in taking down large prey once a week, killing approximately 50 to 60 large animals per year. Although some subspecies can consume up to 34 kilograms of food in one night, most will consume approximately 5 kilograms in one meal, covering the carcass and returning to feed in the following days. If preferred prey stocks are depleted, tigers will opportunistically hunt sub-optimal prey, such as birds, fish, rodents, amphibians, reptiles, primates and porcupines. If found in close proximity to human settlements, tigers may also consume domestic animals, such as cattle and goats.

4. Habitat & Behaviour 

Once inhabiting a wide range of countries across Asia, from Turkey to Russia and on the Indonesian islands of Java and Bali, tigers currently occupy less than 6% of their 1900 AD range. Having been driven to extinction in Singapore (1930s), Bali (1940s), Java and Hong Kong (1960s), central Asia (1970s), the majority of mainland temperate and tropical China (1980s-1990s), and most recently in Vietnam, Lao PDR and Cambodia (2000s), breeding subpopulations are now found in a mere 11 countries. These are: Bangladesh, Bhutan, China, India, Indonesia, Malaysia, Myanmar, Nepal, Russia, and Thailand. Although the species has also been confirmed in Myanmar, southern and eastern subpopulations are believed to depend on immigration from Thailand. 

Despite this recent, drastic range collapse, tigers are habitat generalists and thus occupy diverse environments, such as: estuarine mangrove forests and equatorial rainforests in the Sundarbans and Sumatra; dry deciduous forests within parts of India; tropical rainforests in the Malay Peninsula; and the temperate, evergreen forests of Palaearctic realms in Russia and China. The principal habitat requirement for tigers, and the factor that determines the size of an individual tiger’s territory, is the availability of sufficient prey stocks. Solitary by nature and aggressively territorial, tigers will mark their domain with scent markings (urine and faeces), scratchings on trees, as well as vocalisations. Female tigers typically give birth to litters of three or four cubs and care for them until they are able to hunt, usually by the age of 18 to 24 months. 

Despite the incredibly wide variety of habitats that tiger populations inhabit across Asia, genome sequencing for the identification of signatures of selection and local adaptation among subspecies is still in its infancy. Liu et al (2018) identified possible signatures of adaptive evolution in Sumatran tigers, such as darker pelage (potentially to provide greater camouflage), a smaller body size (potentially to reduce calorific demand and enable the exploitation of smaller prey), and metabolic adaptations to tropical climates. Armstrong et al. (2021) further noted that genomes sequenced from Amur tigers revealed signals of selection on lipid metabolism genes and pathways, associated with possible adaptations to cold climates. Signatures of selection on these lipid metabolism genes have also been identified in two human populations (Greenlandic Inuit and Indigenous Siberians), as well as in polar bears. Finally, given historical records of Bengal tiger occupancy across a significant range of habitats, the subspecies displayed the greatest amount of genetic variation in genome-wide diversity estimates.

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5. Ecological Importance

An apex predator, the tiger plays an incredibly important role in shaping and maintaining the vitality of the ecosystems it inhabits. By consuming herbivorous ungulates, tigers prevent overgrazing and maintain ecological integrity by controlling the density of grazing species. Due to their solitary nature and expansive home ranges, tigers are considered to be an ‘umbrella’ species, as the the conservation of their native habitats confers protection to a large range of naturally co-occuring species. The tiger has also been referred to as a ‘keystone’ species, as the density and health of specific tiger populations is highly indicative of the vitality and integrity of the ecosystem they reside in. The conservation of tiger landscapes further protects at least nine major watersheds, which regulate and provide freshwater for more than 800 million people across Asia. If driven to extinction, the loss of tiger populations across Asia would result in significant disruptions to the integrity, vitality and natural order of countless ecosystems, as well as to the communities that depend on these natural resources for their survival. 

6. Threats

Although the IUCN regards global tiger population estimates as relatively uncertain, the organisation has taken a precautionary approach in designating the species as ‘Endangered’ given their extirpation from several countries since the turn of the century, as well as the fact that numerous populations continue to face severe anthropogenic threats. In some regions, conservation measures have been sufficiently successful to produce stability or even increases in national tiger numbers, such as in India, Nepal, Thailand and Northeast Asia. Nevertheless, Southeast Asia continues to see declines in tiger counts. Although gains in Northeast and South Asia, where tiger densities are higher, may result in an overall increase in global tiger population estimates, the aforementioned genetic diversity and uniqueness of all six subspecies, particularly those under greater threat of extinction, deserve to be safeguarded. The primary threats to tigers are anthropogenic in nature: poaching; habitat loss and fragmentation; prey depletion; and infectious disease.

The tiger has long been a primary target for the illegal wildlife trade, with poachers selling every part of the animal, from whisker to tail, across both local and international markets. Although the species has been protected under Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 1975, as well as under national legislation in numerous range states, the high financial value placed on products such as skins, teeth, bones, meat and organs, coupled with consistent demand for such products, have ensured that the practice continues.

The use of tiger body parts is deep-rooted in certain cultural and medicinal practices within Asia, particularly in China and Vietnam. Tiger bones, used to make wine and tonics in traditional Chinese medicine, are believed to possess numerous healing properties, such as strengthening muscles and relieving pain and inflammation. Tiger skins, canines, claws, and other body parts are typically purchased as symbols of social status and wealth, in the form of ornaments, carpets, coats, or taxidermy trophies, and can fetch up to 70,000 USD.

Between January 2000 and June 2022, approximately 3,377 tigers were confiscated from traffickers across 50 countries: 1,319 whole tigers; 11,528 bones; 1.1 tonnes of meat; 2,737 claws; 1,217 whole skins; 426 skulls; 933 teeth; 469 whiskers; 106 paws; 610 skin pieces; and 13 tails. Nevertheless, these figures are unlikely to reflect the true extent of the trade. Resources for the enforcement of legislation, the conservation of prime tiger habitat, and the apprehension of poachers are often limited in countries where tigers are found, particularly given the lucrative nature of the market. Trade routes in non-government controlled areas, such as the northern region of Myanmar bordering China, are also heavily exploited due to the lack of restrictions or regulations imposed in the area.

Exacerbating the situation is the fact that there are approximately 8,900 captive tigers held across 300 farms and facilities in Asia, predominantly located in China, Lao PDR, Thailand and Vietnam. These establishments, which range from residential basements to licensed battery-cage farms, typically smuggle tiger cubs from the wild and implement captive breeding programs to meet increasing demands from the illegal wildlife market. Although the practice of farming endangered species purports to lessen poaching pressures for wild populations, it has rather been found to further perpetuate the demand for tiger parts by appearing to legitimise and normalise the trade. Captive tigers are kept in appalling conditions, confined to small cages, malnourished, and deprived of the ability to exhibit natural behaviours. Studies have also revealed that consumers of tiger products, such as tiger bone glue in Vietnam, actually prefer to purchase products that emanate from wild tigers, and that these consumers would continue to purchase illegal, wild-caught products regardless of whether legal tiger farming were to exist in more countries.

At present, commercial tiger farms are only legal within China, where the practice was introduced in the 1980s. In 2018, the Chinese government reversed a 25-year ban on the use of tiger bone in traditional Chinese medicine, allowing the use of captive-bred tiger bones in certain circumstances. Despite undergoing a revision in 2020, China’s current Wildlife Protection Law continues to allow the use of captive-bred tiger parts by companies that are authorised to produce and sell tiger bone wine and tiger skins. In 2018, the government of Lao PDR ordered the closure of all tiger farms within the country, however legislative loopholes and weak enforcement have allowed facilities to avoid detection or masquerade as zoos, thus continuing to exploit the species. 

As aforementioned, wild tigers currently occupy less than 6% of their 1900 AD range. Due to the continuous growth of human populations across Asia, land is increasingly cleared or disturbed for infrastructural development, the exploitation of natural materials, as well as the establishment of agricultural farms, settlements, and plantations. Between 2001 and 2019, approximately 610,000 square kilometres of forest was lost in Southeast Asia, primarily for the cultivation and production of rice, palm oil and rubber. Limited resources and opportunities for revenue across local communities further result in their reliance on surrounding ecosystems for their survival. In addition to hunting tigers, which provides a considerable income to poachers, main prey sources such as deer and boar are caught at high volumes for local consumption. With depleted prey stocks and an extremely limited range of habitat, tigers are often seen entering human settlements to catch livestock or domesticated animals, exposing them to the threat of retaliation or poaching.

The fragmentation of breeding populations by large-scale infrastructural or urban development projects also exposes tigers to the risk of inbreeding and atypical phenotypic variation, reducing the fitness and vitality of future generations.

When comparing the genomes of both Amur tigers and Bengal tigers, researchers discovered that Amur tiger populations harboured fewer long runs of homozygosity (ROH) than their Bengal counterparts. Runs of homozygosity arise when offspring inherit identical haplogypes from each parent, indicating potential inbreeding and recessive inheritance due to isolation. While India’s landscape is characterised by variable habitats and extremely high human population densities, the Russian Far East instead hosts more continuous habitats with low human population densities. Inevitably, individual movement within Bengal tiger populations is incredibly hindered, as urban barriers force breeding populations into small, isolated pockets of fragmented land. Left with limited options, individuals in these small populations are more likely to mate with relatives. Amur tigers, on the other hand, face no significant barriers to individual movement. Despite lower population densities, Amur tigers have been shown to be more panmictic, with little or no indications of geographic population substructure. Without habitat connectivity, tiger populations may become locally or functionally extinct in regions where urbanisation and deforestation occur at rapid rates.

Lastly, infectious disease has been described as a potential threat to wild tiger populations. Although the topic remains understudied and thus poorly understood, instances of tiger deaths attributed to canine distemper virus (CDV) have been reported in Russia and India. The virus is particularly threatening to small, isolated tiger populations with limited habitat continuity. In 2004 and 2010, CDV was coincident with a localised decline of tigers in Sikhote-Alin Zapovednik, Russia, with a loss of 16 tigers over the span of four years. Disease further affects main prey stocks for tigers, such as the spread of African Swine Fever in Russia and Indonesia. 

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7. Conservation

As aforementioned, conservation efforts for flagship species, such as the tiger, are typically well funded and garner widespread public attention. However, due to the complexity of threats facing tiger populations across Asia, there is an urgent need for further evidence-based, multifaceted conservation initiatives that are able to reflect the needs of both tiger populations and the local communities that they cohabit with. Given that remaining wild tigers are located in one of the most densely populated regions in the world, coupled with their need for expansive home ranges and their susceptibility to human conflict, conservation strategies should focus on strengthening political will and legislative enforcement to reduce poaching, prohibit the degradation of prime tiger habitat, and to put an end to the illegal wildlife trade, including the closure of tiger farms across Asia. By banning the grant of logging, agriculture, palm oil, and other concessions that typically result in deforestation, and thus expose tigers to inbreeding depression, poaching and increased contact with human settlements, governments and conservationists can work together with local communities in developing strategies to protect tiger habitats, create safe corridors for movement, minimise conflict, and implement sustainable tourism or agricultural practices that benefit both tiger and human populations. 

In 2008, the World Bank established the Global Tiger Initiative, a group comprised of all tiger range countries and tiger conservation stakeholders, which was tasked with developing a collaborative strategy for safeguarding wild tigers from extinction. At the 2010 Tiger Summit, the Global Tiger Recovery Program (GTRP) was launched with the primary goal of doubling the number of wild tigers by the year 2022. This was to be achieved through the implementation of the following actions: the effective preservation, management, enhancement and protection of tiger habitats; the eradication of poaching, smuggling and the illegal trade of tigers, their parts and derivatives; increased cooperation in transboundary landscape management and in combating illegal trade; increased engagement with indigenous and local communities; increased effectiveness of tiger and habitat management; and the restoration tigers to their former range. The performance of each tiger range country in implementing the goals of the GTRP was assessed and scored in order to maintain accountability, and to serve as a mechanism for feedback and improvement. 

In 2022, data released by the IUCN revealed that, while global tiger population counts had risen, the progress was uneven. Bangladesh, Bhutan, India, Nepal, China and Russia had made significant progress towards increasing and protecting regional tiger populations, primarily though habitat protection, strong political will, anti-poaching measures, prey-augmentation, and improved resource allocation. However, in Southeast Asia, tigers continued to face serious threats of poaching, habitat loss and fragmentation, largely due to a lack of investment and inadequate resources. Therefore, at the Fourth Asia Ministerial Meeting on Tiger Conservation in 2022, the South East Asian tiger range countries decided to collectively prioritise common actions through a South East Asia Tiger Recovery Action Plan (STRAP), which accompanied the second Global Tiger Recovery Program. 

The GTRP 2.0, launched in 2023 and is scheduled for review in 2034, contains a set of 56 KPIs to measure progress towards the goal of increasing and safeguarding global tiger population counts. In alignment with the Post-2020 Global Biodiversity Framework, the GTRP 2.0 set out the following overarching outcomes, among others: increased political and financial investment by tiger range country governments, support from funding agencies and the private sector; high-level protection for tiger and prey populations at country and transboundary levels; the implementation of data-driven planning, monitoring, and habitat management for tigers, prey and habitats; effective management of human-wildlife conflict with stakeholder engagement; the promotion of policies for natural resource stewardship and conservation incentives; and significant reductions in legal trade in tigers and their parts in source countries, as well as reduced remand for tiger derivatives in consumer countries. 

Perhaps the most critical conservation action for safeguarding tiger populations is the protection of suitable habitats, which includes maintaining habitat connectivity and augmenting prey stocks. According to the IUCN, governments of tiger range countries must identify and secure ‘source sites’ – protected areas with the confirmed presence of breeding tigers, including population estimates of over 25 breeding females, that are embedded within a larger habitat landscape with the potential to hold over 50 breeding females – as well as habitats beyond protected area boundaries that historically or currently have the potential to support breeding populations or act as corridors.

At present, many source sites are too threatened or degraded to support species recovery, and only 21% of suitable tiger habitats are legally protected, with a mere 9% of these habitats defined as “strictly protected” by the IUCN. Some tiger conservation landscapes remain as designated concessions for resource extraction, such as timber, oil, and plantations, and many protected areas suffer from poor regulatory, budgetary and enforcement effectiveness. Although data on tiger occurrence is becoming increasingly accurate across tiger range countries, there remain data gaps in remote areas of South East Asia, as well as the Himalaya of India, Nepal and Bhutan, that could hold significant recovery potential or accommodate range shifts as a result of climate change.

By allocating greater resources to the identification and strict protection of tiger landscapes, including the implementation of anti-poaching measures, bans on resource extraction projects, and the expansion of protected area boundaries to include habitat corridors, wild tiger populations may begin to recover naturally with increased gene flow between them. Targeted tiger reintroductions and translocations to protected areas within the species’ historical range have already begun in India and Russia, and are planned to occur in Kazakhstan and Cambodia.

Nevertheless, converting areas of habitat into protected tiger conservation landscapes requires not only governmental initiative, but also engagement from local communities and indigenous groups that cohabit with tigers.

In April 2023, as India’s Prime Minister Narendra Modi announced promising increases in national tiger population counts since the launch of Project Tiger in 1973, India’s conservation model for creating protected tiger reserves, indigenous groups protested that such conservation strategies had uprooted communities that had resided in the forests for millennia. A number of Indigenous groups joined together and established the Nagarahole Adivasi Forest Rights Establishment Committee to protest against fortress conservation, under which local communities are evicted from forest regions for the protection of endangered species. Rather than simply evicting indigenous groups, it has been suggested that forests could be collaboratively managed by local communities and government officials, allowing locals to utilise forest resources in a sustainable manner whilst safeguarding the ecosystems within it. This model of community-managed forest conservation has been successful elsewhere, such as in Nepal where locals act as Forest Guardians to safeguard red panda populations. 

Since indigenous groups, many of which hold a cultural or spiritual respect for the environment, derive greater benefit from clean, undisturbed habitats, conservation strategies should focus on banning the grant of concessions on protected land, introducing sustainable opportunities for income, such as eco-tourism or sustainable agriculture, and the implementation of education initiatives in local schools to foster a genuine interest for environmental conservation. Strategies for minimising conflict between human settlements and tigers, such as increasing prey stocks in forests bordering villages, creating suitable habitat corridors, or implementing compensation schemes for farmers that lose livestock, should also be prioritised for the safety of both humans and tigers. 

NGO Spotlight: David Shepherd Wildlife Foundation

Founded in 1984 by David Shepherd CBE, the David Shepherd Wildlife Foundation (DSWF) is a conservation charity operating across Africa and Asia to eradicate wildlife crime and protect endangered species in their natural habitat. By funding and supporting long-term frontline conservation projects in India, Thailand and Russia, funding investigations into the wildlife trade, participating in international policy conventions, lobbying at governmental level, and strengthening law enforcement, habitat protection, and community engagement programmes, DSWF have contributed significantly to safeguarding wild tiger populations and to the ongoing eradication of the illegal wildlife trade.

In 2023, DSWF raised almost £23,000 in their appeal, ‘The Dark Side of the Illegal Tiger Trade’, which highlighted the number of tiger lives lost each year to meet the demand for the illegal wildlife market. Having been provided with long-term support, partners of DSWF have successfully investigated wildlife trafficking routes in Malaysia, Thailand, Myanmar, China, Laos and Vietnam, with the following outcomes: 33 intelligence reports detailing the trade were produced; 28 individuals involved in the trade were identified; one criminal network was mapped; and five tiger facilities of concern were identified. The information from intelligence reports has enabled law enforcement officials in tiger range countries to obstruct the trade of tigers and apprehend those involved. These reports are also utilised by the Financial Action Task Force, an inter-governmental organisation that deals with money laundering and terrorism financing, to determine the role of criminal organisations in tiger farming and highlight the weaknesses in national wildlife legislation, such as in Laos. If, in light of reports of legislative inefficiency, Laos fails to improve laws on tiger farming and trade, the country may face global financial sanctions. 

In India, DSWF supported the training of four K9 Units, which now assist in tracking and apprehending poachers. Their presence in tiger conservation landscapes further acts as a deterrent to potential poachers. A field partner of DSWF, the ‘Rhino and Tiger Goes to School’ programme, has implemented a number of education initiatives to generate awareness about tigers within schools and encourage an interest in conservation. Approximately 3,680 students have participated in the programme so far, all of which reside in villages bordering rhino and tiger habitats. By educating young children about the habitat, behaviour, population, distribution and conservation challenges of endangered species, such as rhino and tigers, the programme is designed to foster genuine care for wildlife from a young age, creating a new generation of conservationists and wildlife protectors.

In Thailand, DSWF has been involved in supporting part protection and law enforcement monitoring work, as well as enhanced ranger training for safeguarding endangered wildlife, such as tigers and pangolins. Thus far, rangers have patrolled around 34,723 kilometres in the past six months, which resulted in the apprehension of 68 poachers and the confiscation of 21 weapons. 

How Can You Help

• Donate to Tiger Conservation. Organisations such as the David Shepherd Wildlife Foundation raise funds to support and finance frontline conservation initiatives across Asia. By donating to their appeals, you can contribute to anti-poaching, habitat conservation, and community engagement efforts, as well as supporting the end of the illegal wildlife trade.
  
• Steer Clear of Tiger Products. Poaching and the illegal wildlife trade are one of the primary causes for the decline in wild tiger populations. If you know anyone that purchases medicinal products, ornaments or other products that contain tiger parts, make sure to let them know of the immense threat that the trade poses to the future of the species.
  
• Don’t Support Zoos or Tiger Farms. When travelling across South East Asia, stay away from facilities claiming to be zoos or those that are clearly tiger breeding farms. These animals are kept in appalling conditions and are likely bred for the illegal wildlife trade.

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Welcome to Earth.Org’s in-depth exploration of the endangered Lankanectes pera, a species of corrugated frogs from Sri Lanka Frogs teetering on the brink of extinction. In this article, we delve into the fascinating world of these remarkable creatures, shedding light on their unique characteristics, ecological importance, and the urgent conservation efforts being undertaken to protect them.

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Between 2012 and 2016, researchers conducting field surveys for Lankanectes in the cloud forests of the Knuckles Mountain Range, Sri Lanka, made a surprising discovery: a new species of frog endemic to the region. Although Lankanectes was previously believed to be a monotypic genus represented by Lankanectes corrugatus, a species of frog found in submontane habitats across southern, western and central Sri Lanka, researchers determined that the newly discovered frog belonged to a morphologically and genetically distinct species. The undescribed frog was named Lankanectes pera in honour of the University of Peradeniya, affectionately referred to as “Pera” by its alumni. The two Lankanectes species were further given the common name of Corrugated Frogs, referring to the numerous and prominent traverse skin folds found on the bodies of both. Although only recently discovered, Lankanectes pera has been evaluated as a Critically Endangered species due to its small population size and limited predicted distribution, as it is believed to be a montane isolate adapted to high-altitude bioclimatic conditions that are currently threatened by climate change and anthropogenic activity. 

Discovery & Evolution

Although numerous endemic anuran lineages exist in mainland India, such as Nasikabatrachus, Micrixalus and Nyctixalus, the only Sri Lankan amphibian lineage that survived the Cretaceous-Paleogene extinction event (66 million years ago) is Lankanectes. Molecular studies of the genus have confirmed its distinctiveness and ancientness among South Asian anuran lineages, and its closest extant relatives are representatives of the Nyctibatrachidae family. Prior to 2018, Lankanectes was believed to be a monotypic genus represented by a single, widely-distributed species, Lankanectes corrugatus.

While conducting field work in the Knuckles Mountain region, specifically on streams found within cloud forests (unique tropical mountainous regions where rainfall is heavy and condensation is persistent, causing a layer of clouds at canopy level), researchers discovered a small population of frogs that appeared to be morphologically different from Lankanectes corrugatus. Noting that a substantial number of Nyctibatrachus species are montane endemics, researchers recognised that the existence of an undescribed species of Lankanectes within Sri Lanka was possible.

By examining the external morphology, genetics and climatic niche of the unfamiliar frog population, researchers ultimately determined that they had discovered a new species of frog, Lankanectes pera, and described their findings in a paper published in 2018 in the journal Zootaxa. With reference to genetic testing, researchers found that the genetic distance observed between the two species of Lankanectes (3.5−3.7% uncorrected genetic distances for 16S rRNA) was consistent with the range of species-level genetic distances commonly founding amphibian sister taxa.

The two species differed in 16 mutational steps (whereas only one to four mutational steps are seen within populations of Lankanectes corrugatus), indicating that they descended from a common ancestor and went their separate evolutionary ways. 

Morphologically, the two species can be distinguished on several subtle but consistent differences. Nevertheless, the primary distinguishing feature between the two species is their habitat range. Lankanectes pera has a much smaller predicted distribution than Lankanectes corrugatus, as the former has only been located in pristine, isolated montane habitat with clear-water streams, sand, rock and canopy cover. In contrast, Lankanectes corrugatus typically occurs in habitats with muddy substrate, such as marshes and rice paddies, where they burrow in mud and plant litter. Researchers believe that the niche endemic habitat of Lankanectes pera, and the specialisations that the species has developed to thrive in such an environment, have prevented it from spreading.

Appearance & Morphology

In their paper, researchers described Lankanectes pera as having a stout body, a dorsally flat and wide head, a large tongue, short but strong forearms, and strong legs. Their fingers and toes are thin, with large, rounded tips, and only their toes are webbed. They do not possess a tympanum, which is a membrane that typically separates a frog’s outer and inner ear allowing the animal to hear in the air and below water. They have tusk-like vomerine teeth, which are present in most species of frogs and are utilised to capture and hold prey. The skin on the head of Lankanectes pera is not co-ossified (in some species of frog, the connective tissue of the dermis ossifies with underlying dermal bones, which may reduce evaporative water loss), while corrugations (prominent dermal folds) and glandular warts are present on dorsal surface of the species’ head, body, forelimbs and thighs. The dorsal side of Lankanectes pera is chocolate brown with irregular dark brown patches, while its chest, belly and ventral sides are white or light brown. 

Habitat and Ecology

The predicted geographic distribution of Lankanectes pera is extremely limited, estimated to be approximately 360km². According to the IUCN, the extent of occurrence of the species is around 89km² and it is believed to have a small population size that occurs in a single, threat-defined location. In fact, Lankanectes pera has been described as a micro-endemic species. In contrast, Lankanectes corragatus has a predicted distribution of 14,120km² and a large population size.

So far, Lankanectes pera has only been observed inhabiting pristine streams that flow through closed-canopy montane forests on the highest peaks of the Knuckles Mountain range (located in the Dothalugala, Bambarella and Riverstone regions of Sri Lanka), at altitudes of 1,250 to 1,600 metres above sea level. These streams are typically characterised by clear, shallow, slow-flowing water with sand and rock substrates. Males are typically found under rock crevices in flowing water, vocalising in chorus at night, but are occasionally heard calling during the day. Lankanectes pera tadpoles are large and inhabit deeper regions of streams where decaying vegetation tends to gather, indicating resource partitioning between adults and tadpoles. The species does not tolerate habitat disturbance.

Ecological niche models have suggested that Lankanectes pera is a montane isolate, adapted to high-altitude bioclimatic conditions. Although it is predicted that suitable climatic conditions are also present in the northern region of the central mountains, this area is climatically and ecologically remote from the current range of the species. 

Ecological Importance 

Although the ecological background of Lankanectes pera has not been studied comprehensively, frogs play a critical role in their respective ecosystems as part of the food chain. Amphibians also play an important part in environmental conservation as an indicator species. When environmental degradation, climatic shifts and pollution affect a habitat, frogs are often among the first casualties and thus provide an early warning signal for ecosystems under threat.

Threats

Since its discovery, Lankanectes pera has been listed as Critically Endangered under the International Union for Conservation of Nature (IUCN) Red List. The species has an extremely small population size and area of occupancy, which is increasingly threatened by climate change and anthropogenic activity. Having adapted to an exceptionally specific, pristine habitat, and intolerant to any form of degradation or disturbance, the continued decline in extent and quality of the Knuckles Mountain Range will ultimately result in the extinction of Lankanectes pera before this remarkable species is properly studied and understood. Cloud forests are an ecologically unique habitat, formed by a delicate combination of climatic and topographical conditions.

These high-altitude, tropical montane environments are characterised by high rainfall and humidity levels, and where, through a process of “lateral cloud filtration”, a layer of clouds or mist persist at canopy level. Air currents that travel inland and encounter high montane slopes gradually cool and form clouds as they rise, resulting in a shroud of fog at high altitudes. These clouds then filter through forest vegetation, condensing on leaves and saturating moss, thereby supporting an incredibly wide range of flora and fauna. The specificity of the conditions in cloud forests, including limited sunlight, cool temperatures, high altitudes, nutrient-depleted soil, high humidity, and the prevalence of dense vegetation, result in high levels of species endemism. Unfortunately, this specificity also renders cloud forests highly vulnerable to global warming and shifts in climate patterns.

In 2022, it was estimated that a mere 1% of global woodlands were categorised as cloud forests, compared with approximately 11% in the 1970s. Annual rainfall has been sharply declining across the Knuckles Mountain region, which has consequently become significantly drier and more seasonal.

From an annual average rainfall of approximately 2,500mm one century ago, the highlands of Sri Lanka now receive between 1,500 and 1,900mm of rain per year. In addition to significant changes in the spatial and temporal distribution of rainfall, global warming has had severe impacts on high-altitude montane environments and their ecosystems. An average annual temperature increase of 0.8C has been recorded across Sri Lanka over the past century, while average temperatures in the highlands have risen annually by approximately 1.1C. In addition to increasing the risk of forest fires, this prevalence of unusually warm temperatures and dry climatic conditions inevitably results in the reduction of moisture and condensation within cloud forests, disrupting the delicate climatic conditions necessary to sustain this unique habitat and the array of endemic and micro-endemic species that rely on it.

Species of flora and fauna that are adapted to inhabiting cooler regions are forced to move to higher altitudes in search of appropriate climatic conditions. This effectively reduces the distribution of sensitive species, isolating them to extremely high-altitude, potentially unsuitable environments. The complete loss of cloud forests, should adverse climate patterns persist, would inevitably result in the mass loss of biodiversity across ecosystems where highly specialised species can no longer find habitats with these unique conditions. 

The Knuckles Mountain Forest Reserve (KNFR) is further threatened by the continuous expansion of agricultural practices, particularly illegal cardamom plantations, and the consequential pollution that accompanies deforestation and pesticide use. A significant portion of primary forest within the KMFR has being cleared to supply fuelwood and timber for surrounding villages, for the cultivation of cash-crops, such as tea, and for the processing of cardamom. Further anthropogenic threats include unregulated research work, the construction of resorts and infrastructure, uncontrolled tourism access, and deliberate forest fires.

Another potential threat to Lankanectes pera is forest dieback, which was first observed within Sri Lanka’s cloud forests in 1978. Although numerous studies have been conducted on the aetiology of forest dieback, it remains a poorly understood phenomenon, although some have expressed concern that a particular environmental stressor that kills extensive strands of woody vegetation may negatively impact amphibians. Research has shown that the acidity from mist and rainwater may threaten highland biota in Sri Lanka, however there is no direct evidence that amphibians are affected; it is believed to have deleterious effects on species that inhabit areas where mist persists for a long time, and that species that can be found in open habitats with aquatic life history stages in shallow, lentic habitats could be more susceptible to this threat. Nevertheless, further research is clearly needed on the subject.

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Conservation

The discovery of Lankanectes pera and their perilous state within the cloud forests of Sri Lanka brought to light the urgent need for conservation measures for unique, climatically-delicate regions that harbour highly specialised species of flora and fauna. Apart from Lankanectes pera, the Knuckles Mountain Range is already known as a critical refuge for at least eight micro-endemic species that are categorised as Endangered or Critically Endangered. Since the habitat requirements of Lankanectes pera are different from those of other threatened micro-endemics, and bearing in mind current predicted global climatic warming models, the implementation of progressive, evidence-based conservation measures are desperately needed to prevent mass loss of biodiversity in the region. 

In 2000, the Knuckles Mountain Range was declared as a conservation forest, effectively banning cardamom cultivation in the region for the protection of the incredible biodiversity found within the range. In 2010, the Knuckles Conservation Forest was further included in the UNESCO World Natural Heritage list. Nevertheless, the consequential socio-economic impacts of the ban on cardamom plantations caused significant hardship for local farmers, who had lost their primary source of livelihood. Subsequent studies on the effects of cardamom cultivation demonstrated that the practice altered forest structure, canopy openness, species composition, soil properties, watershed properties, natural regeneration and evolution processes of the Knuckles Mountain Range, resulting in various deleterious environmental effects.

Negative modifications of ecosystem services, such as the reduction of water quality, depletion of genetic resources, and soil erosion, rendered cardamom cultivation an unsustainable source of income for surrounding communities. Therefore, the ban was upheld and a holistic approach was suggested for creating alternative sustainable sources of income for villagers in the region, including engagement in the tourism industry to support and reap the benefits of the World Natural Heritage status of the range. While these initiatives are a positive step towards the sustainable protection of forest habitats, continued and strengthened management of protected areas, particularly where Lankanectes pera occurs, and additional protection of potentially suitable streams and forests elsewhere in the mountain range are crucial.

Nature-based solutions focusing on ecosystem services have also been widely discussed in relation to cloud forests. In approximately 25 countries where cloud forests are found, hydropower dams are used to produce electricity and over half of these rely on water from cloud forests.

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It has been suggested that implementing a tax on existing dams could cultivate a revenue stream for the protection of these sources of water, which would make the protection of forests a more prosperous choice when compared to clearing forests for agriculture and timber. This prospect is of particular interest in countries where environmental conservation measures are inadequate or often bypassed for economic reasons. While it is still unclear whether profit-motivated initiatives are a sustainable, ethical option of the protection of natural ecosystems, cloud forests are fundamentally important for the survival of an incredibly wide variety of flora and fauna, as well as for indigenous communities, and desperately require more attention from conservationists.

Lastly, and most importantly, Lankanectes pera requires a specific species conservation plan, supported by further research and monitoring initiatives. Given the multitude of threats that this species faces, and the limited knowledge on the behavioural patterns, breeding seasons, mating practices, ability to produce offspring, development, and ecology of Lankanectes pera, designing an effective conservation plan is difficult at present. Nevertheless, Peradeniya University is well equipped to lead the implementation of conservation measures, with some of the best academics in the fields of science and humanities within such close proximity of the habitat of Lankanectes pera. Although the present known habitat of Lankanectes pera is surrounded by Lankanectes corrugatus, effectively creating a genetic barrier for the spread of Lankanectes pera to further mountain ranges, authors of the 2018 study noted that relict populations that are genetically similar to Lankanectes pera could inhabit adjacent Central Highlands, indicating that there is still much to learn about the genus Lankanectes.

Featured image: Senevirathne et al (2018)

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With the last common ancestor diverging in the Cretaceous period, Borneo’s endemic dragon-like living fossil – the earless monitor lizard – still mesmerises herpetologists and animal lovers worldwide.

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Taxonomy

Class: Reptilia
Order: Squamata
Superfamily: Varanoidea
Family: Lanthanotidae
Genus: Lanthanotus
Species: Lanthanotus borneensis

Geography

Subcontinent: Southeast Asia
Countries: Malaysia, Indonesia
Native habitats: Lowland rainforests, near streams

Size of Adults

Length: 20-25 cm (snout-to-vent) and 40 cm (total)
Weight: Approximately 0.5 to 1.5 kg

Borneo (in Malaysian), or Kalimantan (in Indonesian), is the third-largest island in the world. Considered one of the most beautiful landscapes in Southeast Asia, Borneo is also a home to an impeccable diversity of rare wildlife species, like the Borneo orangutan (Pongo pygmaeus), Sumatran rhinoceros (Dicerorhinus sumatrensis harrissoni), the sun bear (Helarctos malayanus), the eight-banded barb (Eirmotus insignis), the Borneo pygmy elephant (Elephas maximus borneensis), the Rhinoceros hornbill (Buceros rhinoceros), and many others. 

Among them, the special place holds the bizarre-looking lizard species – Borneo Earless Monitor (Lanthanotus borneensis). Being the sole living species in the Lanthanotidae family, it shares its lineage with true monitor lizards. This species stands alone without any contemporary counterparts, and its most recent common ancestor is believed to have diverged in the Cretaceous period, around 145 to 66 million years ago. 

Appearance and Habitat

One of the most striking features of this exotic lizard is its prehistoric look and resemblance to a miniature flightless dragon or dinosaur. They lack ear openings (hence the name), but they can hear. The lizard also exhibits an elongated body with a relatively long neck, accompanied by small limbs. The blue eyes are magnificently contrasting with brown armoured skin, making the lizard even more enigmatic.

The lizard is semi-aquatic, preferring to live near streams and marshes in lowland rainforests, as well as in anthropogenic habitats like agricultural land, mature fruit tree gardens, and palm oil plantations. 

This species is also known to potentially occur in rice paddies. The streams it populates are typically rocky. Its tropical habitat maintains air and water temperatures ranging from approximately 22-29C (71.6-84.2F), with captives reportedly preferring temperatures between 24-28C (75.2-82.4F). In areas densely populated by earless monitor lizards, the water is clear with a neutral acidity (pH). This species also shares microhabitats with Tropidophorus water skinks.

Diet and Behavior

The species is known to hunt earthworms, freshwater crabs, and catfish. Additionally, in captive conditions, individuals have demonstrated a preference for chopped red meat, fish, and frogs. Other dietary preferences include insects like crickets, cockroaches and grasshoppers. 

While generally docile and inactive when handled, male earless monitor lizards exhibit more aggression than females. Despite historical dissection studies initially suggesting an absence of venom, a 2020 study has identified venom glands and toxic compounds, primarily kallikreins, in their bites, although the venom’s blood-clotting effects are comparatively weaker than those of many other venomous reptiles.

Population and Conservation Status

Borneo Earless Monitor is an extremely rare animal due partly to its reclusive lifestyle. It has been categorised as ‘Endangered’ by the IUCN Red List of Threatened Species. Only about 150 specimens were collected over a century and a half from fewer than 15 confirmed localities. Several habitats may have been lost due to deforestation, resulting in the surviving population being severely fragmented. While the true area of occupancy is unknown, recorded occurrences correspond to an area of approximately 52 square kilometres (20 square miles).

The rarity and mystery surrounding this animal have led reptile enthusiasts to affectionately dub it “the Holy Grail of herpetology.” 

Earless monitor lizards face significant threats primarily from human activities, including trapping for the pet trade and hunting for their skin in the leather industry. Additionally, habitat loss poses a severe danger to this species, with Borneo’s rainforests swiftly giving way to the expansion of oil palm plantations. 

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Although the rate of forest loss in the Earless Monitor’s habitat has been slightly below 30% over the past 18 years, the absence of information regarding the species’ generation length raises concerns. The lizard’s dependence on a specific lowland forest habitat, coupled with the elevated risk it faces, suggests that the decline in suitable habitat, and consequently the lizard population, may have surpassed 30% over three generations. 

The unique characteristics of the Earless Monitor lizard have sparked considerable international interest in herpetoculture, leading to a demand in the pet trade. This demand escalated rapidly after traders identified potential collecting sites, posing a significant threat to the species as individual subpopulations are believed to be small and vulnerable to collecting pressure.

Featured image: kuritafsheen77/Freepik

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Have you ever heard about the giant animals, the American Bison and the European Bison? These huge creatures have two different tales, but they are both fascinating. Let us explore where they live, what is happening with them today, and the fantastic efforts to keep them safe. In a world that is changing fast, these endangered bison are still symbols of wild beauty and the hard work of many people.

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Meet the Mighty Bisons

Before we dive into their conservation, let us get acquainted with the two bison species. First, let’s meet the American bison (Bison bison). 

These bison, often called American buffalo, naturally inhabit North America. They are the biggest land animals on this continent and are known for their humpbacked appearance. You can mostly spot them in the United States and Canada. Yellowstone National Park and the Grand Teton National Park are well-known spots for witnessing these impressive creatures in the United States. In Canada, bison populations thrive, particularly in Alberta and British Columbia. 

At one point, it is believed there were tens of millions of them, but due to excessive hunting, loss of their natural habitats, and diseases, their numbers dropped dramatically, almost pushing them to the brink of extinction in the late 19th century. Today, they are considered “Near Threatened,” according to the International Union for Conservation of Nature (IUCN).

Now, let’s turn our attention to the European bison (Bison bonasus), also known as the wisent. 

These magnificent creatures inhabit the ancient woodlands and grasslands of Europe. You can find them in various European countries, including Poland, Belarus, Russia, Ukraine, and Lithuania, where they have established populations. One of the prime spots to catch a glimpse of these remarkable animals is the Białowieża Forest, stretching across the borders of Poland and Belarus. While they share some similarities with the American bison, European bison have subtle differences in their physical traits. 

These resilient creatures were once on the edge of vanishing from the wild, but thanks to dedicated efforts, their numbers have rebounded, even though they are still considered “Near Threatened” by the IUCN.

Current Status and Population of Bison

According to the population estimates, the bison population is categorised at both the species and subspecies levels. 

At the species level, a total population of 31,000 individuals is distributed across 68 conservation herds. Among these, the number of mature individuals falls between 11,000 to 13,000. The bison population at the subspecies level can be further broken down into Plains bison, accounting for 20,000 individuals, and Wood bison, with a population of 11,000 individuals. These figures offer valuable insights into the current state of bison populations and underscore the significance of ongoing conservation efforts to protect these magnificent creatures.

As the biggest wild land animal in Europe, the European bison used to roam freely all over the continent. But as time passed, hunting and losing their homes caused their living areas to get smaller and smaller. Things got so bad that by 1927, the very last wild European bison was killed in the Caucasus, and only 54 of them were kept in captivity. However, these bison have made an amazing comeback thanks to different plans to help them reproduce and release them back into the wild. In the last 10 years, the number of free European bison has gone from around 2,579 to 7,000. The biggest groups of these bison can be found in Belarus and Poland. 

Conservation Efforts

Bison conservation is a global mission that unites people across borders and communities and involves various crucial initiatives. One key effort is reintroduction programmes, where organisations work hard to bring bison back to their original homes. These programmes aim to bring balance to ecosystems and reestablish these magnificent animals in the places they once called home. In North America, bison ranching and commercialising bison products have emerged as a sustainable way to support bison conservation. The market for bison products is steadily growing, promoting the protection of these species. 

Additionally, conservation breeding programmes in captive facilities are vital in increasing bison populations and ensuring the genetic diversity needed for their long-term survival. Another essential aspect of bison conservation is habitat restoration, which focuses on preserving and expanding the grasslands and woodlands where bison freely roam. 

More on the topic: Breeding Programmes For Endangered Species: Do They Really Help?

Legal protection and creation of national parks and reserves have been significant factors in safeguarding bison populations. Notably, the American Bison earned the distinction of becoming the national mammal of the United States in 2016, underscoring its importance. Moreover, indigenous communities in North America have been prominent leaders in bison conservation efforts, with many tribes actively involved in restoring bison populations, considering these animals as essential to their cultures and traditions. 

In the world of bison conservation, the story is not just about safeguarding an animal; it is about rekindling a deeper connection between humanity and the untamed spirit of the wild. Together, these initiatives form a vibrant, ever-evolving composition that reminds us that, with passion and persistence, we can revive the dreams of a harmonious coexistence with the wild. As bison once again thunder through the plains and forests, they serve as living testaments to the indomitable human spirit to preserve the magic of the untamed world.

The bison’s tale is one of hope, a reminder that our actions can make a difference. Will you join the effort to safeguard these living legends and their habitats? The future of the bison rests in our hands.

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