Some of the world?s most unique and vulnerable animals are found in Australia. From cute and cuddly koalas to deadly vipers, these species have evolved in isolation over 55 million years. However, settlement by Europeans since 1788 has led to habitat destruction, environmental pollution, hunting, and the introduction of non-native predators such as cats and foxes, which have driven a large number of Australian animals to extinction over the last 200 years. But what if some of these species aren?t really gone? At least, not forever. Sometimes, in a fortunate twist of fate, so-called ?Lazarus species? appear to come back from the dead after being declared extinct. Rediscoveries of these elusive animals spur hope to find and protect other lost species. Here are 10 Australian extinct animals making a remarkable comeback.
Mountain Pygmy Possum
One of the most notable Australian extinct animals, the mountain pygmy possum was first discovered from Pleistocene fossil remains found in 1895. The species was presumed extinct until the unexpected discovery of a living specimen at a ski lodge at Mount Hotham, Victoria in 1966. Small colonies were subsequently found in Kosciuszko National Park in 1970 and on Mount Buller in 1996. Unlike other Australian marsupials, the mountain pygmy possum lives in alpine regions and hibernates during the winter. It requires continuous snow coverage of at least one metre for up to five months a year. Due to its unique habitat requirements coupled with global warming, there are currently only small patches of suitable habitat remaining for this species. The three remaining populations are also threatened by introduced predators such as foxes and cats, both of which have rapidly expanded their ranges since their introduction to Australia. As of 2017, there are less than 500 mature mountain pygmy possums in the wild.
Central Rock Rat
The central rock rat is one of the many Australian extinct animals that have made a return. It was first described by Edgar Waite during the Horn Scientific Expedition of 1896, and was considered rare at the time ? although specimens were collected from a variety of rocky habitats in the arid regions of central Australia. Two individuals collected from the Tanami Desert in 1952 were the last seen before the species? first disappearance, until a chance discovery by a stockman in 1960 spurred several attempts by researchers to find surviving populations. These expeditions proved fruitless, and by 1990, the central rock rat was presumed extinct. In 2000, following a period of high rainfall, the species reappeared for the second time and was found to be thriving in parts of its former range. However, the population declined considerably following drought and wildfires, which affected much of central Australia. Trapping efforts from 2009 to 2012 recovered only nine individuals. As of 2013, small populations of the central rock rat are believed to persist in the MacDonnell Ranges, however their distribution remains unknown.
The Lord Howe Island stick insect was rediscovered by climbers on a remote, volcanic sea stack. Image credit: Rohan Cleave, Melbourne Zoo
Lord Howe Island Stick Insect
Lord Howe Island, a small volcanic island in the Tasman Sea, was settled as a whaling colony in the 19th century. At the time, large insects called ?tree lobsters? were abundant on the island and were subsequently named Lord Howe Island stick insects. They were believed to have been hunted into extinction just 30 years after black rats were introduced to the island in 1918. In 1964, climbers exploring a nearby island known as Ball?s Pyramid reported the discovery of a dead Lord Howe Island stick insect. In the decades that followed, scientists led several unsuccessful missions to find living specimens. However, in 2001, three living insects were discovered on a rocky ledge of the island. It was the first confirmed sighting of the species in over a century. A captive breeding population has since been established at Melbourne Zoo, and the population remaining on Ball?s Pyramid is protected by authorities.
The mahogany glider is a small species of gliding possum that was first described in 1883 by Charles Walter de Vis, a noted zoologist. As a result of habitat destruction and predation by introduced species, the species disappeared shortly after its discovery. It was believed to be extinct for more than a century. However in 1989, a small group of mahogany gliders were rediscovered, and a recovery plan was developed by the Queensland government to protect their habitat. A captive breeding program has since been established at David Fleay Wildlife Park. There are an estimated 1,500 mahogany gliders currently left in the wild.
Considered extinct for almost half a century, the bridled nail-tail wallaby is now protected and making a comeback. Image credit: Queensland Government
Bridled Nail-Tail Wallaby
The bridled nail-tail wallaby, one of the more notable Australian extinct animals, is a small marsupial named for its distinctive white ?bridle? marking and nail-like spur at the tip of its tail. It was historically found throughout semi-arid eastern and south-eastern Australia, however habitat destruction and predation by introduced species led to its decline in the late 19th and early 20th centuries.
After almost 50 years with no confirmed sightings, the bridled nail-tail wallaby was believed to be extinct. However, in 1973, reports of a surviving population on a property near Dingo, Queensland were confirmed by scientists. The property was converted into Taunton National Park; a nature reserve dedicated to the protection of the bridled nail-tail wallaby. The only naturally occurring population remains in this area, however small groups of individuals have been re-introduced to habitats in south-west and central Queensland. Today, the wild population is estimated to be between 500 and 1900 mature individuals.
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Having remained virtually unchanged for 60 million years, the dinosaur ant is the most primitive ant species and is considered a ?living fossil?. It was first discovered in 1931, when an entomologist collected two individuals during an insect survey near Russell Range in Western Australia. Researchers subsequently led a series of attempts to find living colonies, but after three decades of searching, the species remained lost to science.
Then, in 1977, a thriving population was discovered in Poochera, South Australia. Surveys in the years that followed uncovered additional populations, and the dinosaur ant is now known to occur in at least 18 locations across the Eyre Peninsula in South Australia. It is currently protected under the Western Australian Wildlife Conservation Act.
Leadbeater?s possum is an elusive marsupial species adapted to living in the canopy of some of Australia?s tallest trees. It is nicknamed the ?fairy possum? for its small size and its habit of darting through the forest at dusk. From its discovery in 1867 until 1909, only five individuals were found. Following this, the species seemingly disappeared, and the Black Friday fires of 1939 were thought to have wiped out whatever remained of the population. In 1961, naturalist Eric Wilkinson ventured into Victoria?s Central Highlands, determined to prove that the possums could still exist. After searching extensively, he eventually spotted one of the elusive creatures on a mountain ash tree near Cambarville. Scientists confirmed the sighting, and subsequent searches found several colonies throughout the surrounding eucalypt forests. Leadbeater?s possum is currently listed as critically endangered, and remains at risk of extinction from logging, climate change, and predation. However, efforts to save the species are being supported by the Victorian Government, as well as volunteer conservation groups.
The armoured mist frog was found to have survived a deadly fungus responsible for mass amphibian deaths around the world. Image credit: Robert Puschendorf, James Cook University
Armoured Mist Frog
One of the more interesting Australian extinct animals that have made a comeback, the armoured mist frog, sometimes referred to as the ?little waterfall frog?, was first discovered in 1976. Although it was once abundant along fast-flowing creeks and streams in north-eastern Queensland, it suffered a dramatic decline in the late 1980s and early 1990s following an outbreak of disease caused by chytrid fungus. It eventually disappeared completely, and most researchers believed it to be extinct. In 2008, a university student conducting research on another species in the Wet Tropics World Heritage Area unexpectedly discovered a small population of what he believed were armoured mist frogs. Researchers conducted DNA tests on the frogs and confirmed they were the elusive armoured mist frog. Intriguingly, most of the frogs were found to be infected with chytrid fungus, however they seemed to have developed a degree of resistance to the disease that caused their decline 22 years previously. As of 2013, the single remaining population has an estimated size of 500 to 1,000 mature individuals.
There were once three subspecies of the Tammar wallaby, which were prevalent in distinct populations in mainland South Australia, Western Australia, and Kangaroo Island respectively. Shortly after European settlement, all three subspecies suffered dramatic declines due to extensive habitat clearance and predation by introduced foxes and cats. The South Australian subspecies was considered extinct by the 1930s, however was re-discovered on Kawau Island, New Zealand in 2001. A re-introduction plan was subsequently developed by the Commonwealth and South Australian governments, and a group of 85 adult wallabies and seven pouch young were reintroduced to their native South Australian habitat in 2004.
Gilbert?s potoroo was discovered by English naturalist John Gilbert in 1840, and was described as a ?rat kangaroo? for its small size and disproportionately long hind legs. A few specimens were collected throughout the 1840s to 1870s, but by 1909, it was believed to be extinct.
In 1994, a PhD student was studying the population genetics of quokkas, and set traplines in Two Peoples Bay Nature Reserve, Western Australia. In November, she discovered two unknown marsupials in the traps, initially believed to be juvenile quokkas. However, after discovering that one of the animals had pouch young, she took an ear-clipping. More of the unusual animals were captured in subsequent traps, and a few were transported to the reserve research station. Scientists from the Australian Department of Conservation and Land Management?s Wildlife Research Centre were able to identify them as Gilbert?s potoroos, thus resurrecting a species that had eluded science for almost a century. Still under threat from human-induced environmental changes, Gilbert?s potoroo is the most critically endangered marsupial in the world. However, individuals can still be found in the low, dense vegetation of Western Australian heathland, and translocated populations have been successfully established at Bald Island and Michaelmas Island.
What Can We Do?
The search for lost species has never been more important than it is today. In the midst of a global extinction crisis, species are disappearing at an unprecedented rate. Australia alone is responsible for an average of four extinctions per decade. But remarkable occurrences of Lazarus species prove that in some cases, despite impossible odds, life finds a way. It is possible for more Australian extinct animals to make a return.
?Nature can come back if you give it a chance,? renowned ethologist and environmentalist Dr Jane Goodall DBE said in an interview for Chatham House. ?More and more people are working to make that happen.? One notable example is Rewild, an organisation founded by a group of scientists in collaboration with actor and conservationist, Leonardo DiCaprio. Dedicated to ?protecting and restoring the wild?, Rewild has compiled a list of 2,100 lost species, and funded numerous search-and-recover expeditions. Already, their efforts have resulted in conservation success stories, including the rediscovery of the silver-backed chevrotain; a Vietnamese mouse-deer missing since 1981.
Featured image by: Department of Environment & Primary Industries Victoria