Leadbeater's possum (Gymnobelideus leadbeateri) is a critically endangered animal found mainly in small areas of alpine ash, mountain ash, and snow gum forests in the Central Highlands of Victoria, Australia, north-east of Melbourne. In June 2025, it was reported that a camera trap near Yarrangobilly Caves in Kosciuszko National Park, Southern NSW, captured an image of a single possum in October 2024. This species is primitive, relict, and does not glide. As the only member of the genus Gymnobelideus, it represents an ancient form of life. In the past, Leadbeater's possums were more common in the limited areas they lived in. They need food available all year and tree holes for shelter during the day, which limits them to mixed-age wet sclerophyll forests with thick Acacia growth in the middle layers. The species was named in 1867 after John Leadbeater, who was a taxidermist at Museum Victoria at the time. It is also known as the fairy possum. On 2 March 1971, the state of Victoria designated Leadbeater's possum as its official faunal emblem.
History
Leadbeater's possum is believed to have evolved about 20 million years ago. It was not found until 1867 and was first known only through five samples, with the last one collected in 1909. After that, the worry that it might be extinct became almost certain when swamps and wetlands near Bass River in south-west Gippsland, Australia, were drained for farming in the early 1900s.
By 1939, during the Black Friday fires, the species was thought to be extinct. However, on 3 April 1961, a member of the species was found again by naturalist Eric Wilkinson in forests near Cambarville. The first sample in over 50 years was captured later that month.
In 1961, a group of Leadbeater's possums was discovered near Marysville. Since then, searches have shown that the current population lives in the highlands. Suitable habitat is essential: forests must not be too old or too young. Conservation efforts include protecting old-growth forests and allowing younger forests to grow old enough to form hollows for nesting.
A mix of 40-year-old regrowth (for food) and large dead trees left standing after fires (for shelter and nesting) helped the Leadbeater's possum population grow to about 7,500 in the early 1980s. After reaching this peak in the 1980s, the population was expected to drop sharply, possibly by 90%, due to limited habitat. The population has decreased rapidly since 1996. The February 2009 Black Saturday bushfires destroyed 43% of the possums' habitat in the Central Highlands, reducing the wild population to about 1,500. A study in 2014 found there is a 92% chance the Leadbeater's ecosystem in the Victoria central highlands will collapse within 50 years.
Habits
Leadbeater's possums are rarely seen because they are active at night, move quickly, and live in the upper parts of very tall forest trees. They measure about 33 cm (13 inches) in length, including their tails. These possums live in small family groups of up to 12 individuals, including one pair of parents that mate only once each year. Each pair may have up to two young, called joeys. All group members sleep together in a nest made of shredded bark inside a tree hollow, located between 6 and 30 meters above the ground. These nests are usually found in the center of a territory about 3 hectares in size, which the group actively defends. The social structure of Leadbeater's possums is led by a single female who ensures that outsiders are not allowed into the group. Young females are separated from the group before they reach sexual maturity. Female Leadbeater's possums are more aggressive than males and often fight with other females, including their own daughters. Because of these frequent conflicts, young females leave the group earlier than their male siblings, leading to a high ratio of males to females (3:1).
Solitary Leadbeater's possums struggle to survive. When young males leave their family group at about 15 months old, they either join another group as extra members or form bachelor groups while searching for a mate.
At dusk, Leadbeater's possums leave their nests and search for food in the lower parts of the forest canopy. They often leap between trees and require continuous understory vegetation to move safely. Their diet includes a variety of plant materials, such as sap and exudates from wattles, lerps, and a large number of arthropods found under the bark of eucalypt trees, including spiders, crickets, termites, and beetles. Plant exudates provide 80% of their energy, but the protein from arthropods is necessary for successful breeding.
Young are usually born at the start of winter (May and June) or late spring (October and November). Most litters have one or two young, who stay in the pouch for 80 to 90 days before leaving the nest. Newly independent young are at risk from owls.
As of 2013, Leadbeater's possums live in three types of habitats: lowland swamp gum forests in the Yellingbo Nature Conservation Reserve; montane ash forests, which are wet sclerophyll forests dominated by mountain ash, shining gum, and alpine ash with a dense mid-story of acacia species; and sub-alpine woodlands in Mount Baw Baw, Lake Mountain, and Mount Bullfight.
Threats
Leadbeater's possums and their forest home have been studied in the longest research project ever done for any animal. This study, led by David Lindenmayer, a professor at the Australian National University, and his team since 1983, has produced hundreds of scientific papers, articles, and books. The research shows that the possums need forests that are not too old or too young. Conservation efforts include protecting old-growth forests and allowing younger forests to grow until they can form tree hollows. Clearfell logging and salvage logging (after bushfires) have been the biggest threats to the possums over the past 30 years.
The entire Central Highlands population lives in a 70 by 80 kilometre area. In February 2009, bushfires destroyed 43% of the possums' known habitat in areas around Toolangi, Marysville, Narbethong, Cambarville, and Healesville. Because of this, the species is now in danger. In December 2012, David Lindenmayer and Dan Harley, a biologist from Zoos Victoria, asked the federal government to change the possum's status to "critically endangered." The then environment minister, Tony Burke, agreed and sent the request to the scientific committee under the EPBC Act. On 22 April 2015, the committee decided to relist the species as critically endangered.
The only other population outside the Central Highlands is at Yellingbo Nature Conservation Reserve. Harley estimates this group has fewer than 50 possums.
Because the species is endangered and lives in a limited area, logging continues to threaten it. In 1993, logging of a five-hectare reserve near Powelltown happened due to a mapping mistake. This caused the possum population to drop by 1997, as its habitat was reduced to a 50-square-kilometre area. Peter Preuss, a researcher, said a breeding program needs to be restarted.
A joint government plan to save the species has not been successful. By the 1980s, the population had dropped to about 2000, even before the Black Saturday fires. In 2007, government-backed company VicForests bulldozed firebreaks through monitoring stations, killing more possums and preventing breeding between colonies.
David Lindenmayer has said that the need for nest boxes shows logging is not sustainable for species like the Leadbeater's possum, which rely on tree hollows. Studies show clear-felling, such as logging in state forests near the Yarra Ranges National Park and Mount Bullfight Conservation Reserve in 2006, killed most possums in the area. Adult possums are strongly attached to their home range and avoid moving.
Salvage logging after fires has further endangered the species. In 2010, VicForests approved clear-felling in unburnt areas like Kalatha Creek in Toolangi State Forest, a decision opposed by the Yarra Ranges Shire Council.
In 2012, MyEnvironment challenged VicForests in court over planned logging in Toolangi forest. They argued that logging had not followed proper surveys in areas that meet Leadbeater's possum habitat. The case was lost due to outdated guidelines and forestry rules. MyEnvironment appealed, but the court rejected the appeal.
Feral cats were once thought to be a minor threat, but recent research shows cats hunt possums near nesting boxes and have possum remains in their stomachs. Cats are now seen as a major threat, especially in areas already damaged by logging or fires.
On 27 June 2013, the Napthine government passed laws allowing VicForests to log Victoria's forests for 25 years and to self-monitor logging. This decision followed previous court cases that blocked logging in possum habitat. The Wilderness Society said the laws risk the survival of the remaining 500 or so possums. These changes to the Sustainable Forests (Timber) Act 2004 will affect biodiversity, carbon storage, and water catchments in the forests.
Conservation
On April 22, 2015, Greg Hunt, the Environment Minister, announced that the Leadbeater's possum would be listed as a "critically endangered" species under the EPBC Act.
The forestry industry and Barnaby Joyce wanted the Leadbeater's possum to be removed from the critically endangered list. After strong reactions from the logging industry and the National Party, the possum's status was placed under re-evaluation. On the night before an ABC 4 Corner episode titled "Extinction" (June 24, 2019), then Environment Minister Sussan Ley announced that the possum would again be listed as "critically endangered."
Approximately 30% of the Leadbeater's possum's ash forest habitat is protected. The remaining area is used for logging.
There is also a small, genetically different group of Leadbeater's possums living in the Yellingbo Nature Conservation Reserve. This area is a lowland habitat dominated by Sedge-rich Eucalyptus camphora Swamp.
In 2013, a proposal was made to create the "Great Forest National Park" to protect the mountain ash forest. The park would cover the area between Kinglake, Baw Baw, and Eildon national parks. This region is important for Melbourne's drinking water and acts as a carbon sink.
Since 2004, the Friends of Leadbeater's Possum community group has worked to raise awareness and support for the possum's conservation.
Through a joint community and government program called "Project Possum," about 200 plastic nest boxes were placed in the wild. Many of these boxes were funded by a community fundraising campaign. The nest boxes help monitor the possum population and support the possums as their forest habitat decreases. Project Possum focused on two forest types: montane ash forest (e.g., Mt Ritchie, Dowey Spur, Ben Cairn) and sub-alpine woodland (e.g., Mount Baw Baw, Lake Mountain, Mount Bullfight). These boxes are checked every one or two years. Nest boxes in sub-alpine woodlands are often used, while those in montane ash forests are rarely used. An additional 50 nest boxes were planned for installation between 2015 and 2016.
Des Hackett is credited with being the first person to successfully breed the Leadbeater's possum in captivity. In May 2006, the last Australian Leadbeater's possum at Healesville Sanctuary died. In January 2010, Kasia, the last captive Leadbeater's possum worldwide, died at Toronto Zoo. In early 2012, a feral cat killed some of the few remaining Leadbeater's possums at Lake Mountain after the 2009 bushfire. This led to three possums being moved to captivity for safety. One of these possums later died. There are no plans to release the remaining two animals, even though new groups of Leadbeater's possums were found at Lake Mountain in recent years. These two possums are now displayed in the Nocturnal House to represent their species. Healesville Sanctuary's breeding program for Leadbeater's possums began again in May 2012. It includes six individuals from the genetically different Yellingbo population. As of May 2015, these possums are kept in large enclosures off display but have not yet bred.