A currently contentious and highly publicised topic, Victoria’s Leadbeater’s Possum (Gymnobelideus leadbeateri) has been our state’s faunal emblem since 1971 and is an ancient, arboreal species of marsupial that is thought to be around 20 million years old. The species was named after one of Melbourne Museum’s chief taxidermists, John Leadbeater, although it also goes by the common name of the Fairy Possum.
Newly listed as a critically endangered species and known for its habitation of old-growth forests, this possum has been continuously spoken of in both political and ecological circles for the past few years. This is primarily due to the species’ significance in regards to logging debates and the potential development of the Great Forest National Park in Victoria, as well as its now critical population status. The following are some vital facts regarding this species for those interested in learning more about the unfortunate plight of our unique faunal emblem.
The soft coat of the Leadbeater’s Possum is grey on the upper body, and cream on the underside and cheeks. Below each cheek is a dark brown stripe of fur, whilst another similarly coloured stripe extends along the upper body from the head to the tail. Their tail is narrow at the base, but extends into a broader shape towards the tip, growing up to 165mm in length. Their body as a whole has been measured at up to 170mm, and generally weighs between 100 and 165 grams. The species also possesses large, rounded ears of a thin texture.
The diet of this small possum ranges from tree sap to various invertebrates. Favoured saps and gums, also known as exudates, include wattle and eucalypt manna as well as honeydew, whilst consumed arthropods vary from crickets, beetles and moths to ants and spiders.
BEHAVIOUR & LIFE HISTORY
As a fast and agile climber, the Leadbeater’s Possum spends a lot of its time climbing and foraging for tree sap and insects in its arboreal habitat. Surviving up to five years in the wild and up to 13.5 years in captivity, this possum species lives in matriarchal (female-dominated) colonies of up to 12 individuals, with only one pair in each colony breeding each season. Other members of the colony typically include one or more generations of offspring, and some unrelated males. Due to their communal living habits, these possums build nests of shredded bark to accommodate the colony in the hollows of generally larger, older trees. They are known to fiercely defend their territory surrounding the nest (1.5 to 3 hectares) from other groups of their species. As they occupy some of the tallest forests in Australia and are nocturnal, individuals are rarely sighted in the wild.
Breeding can take place up to twice a year in the Spring and Summer period, and then the Autumn and Winter period. Each litter consists of up to two joeys, and females are able to breed again within the same season if the first litter is unsuccessful. As marsupials, Leadbeater’s Possum joeys remain in the mother’s pouch for approximately 12 to 13 weeks and are then weaned when they are about four months old. When female offspring reach an age of 10 to 12 months, they must disperse to other territories following their eviction from the colony.
RANGE & HABITAT PREFERENCE
This species is distributed across the Central Highland forests of Victoria, whilst a more isolated population is located closer to Melbourne in Yellingbo. Various factors may influence a colony’s choice of habitat, such as the number of old, hollow-bearing trees for nesting, density of wattle trees and various shrubs in the forest understorey, and the connectivity of the area that may or may not allow individuals to move throughout their territory. The forests they reside in typically contain a significant amount of Mountain Ash (Eucalyptus regnans) trees, whilst the presence of various species of Acacia shrubs may also be an important factor in habitat choice based on the possum’s dietary preferences. Regrowth following fire has also been found to be an extremely significant factor in regards to range and habitat.
As of April 2015, the Leadbeater’s Possum has been classified as critically endangered. This classification means that this species is now viewed as being under our nation’s highest level of protection in regards to environment law. Various threats could be to blame for the 80% decline of the species since the 1980s, including the devastating effects of Victoria’s 2009 bushfires on the hollow-bearing trees that the species call home, as well as the logging that takes place before and after fires that may otherwise have left some habitat remaining for the possums.
However, this is not the first time that the Leadbeater’s Possum has been under serious threat. In 1921, the species was declared extinct, as no individuals had been sighted since 1909. It was not until 1961 that an individual possum was found and captured in forests close to the rural area of Cambarville, Victoria. In the same year, a colony was found not far from Marysville and, since then, searches have yielded sightings that suggest the existing population is focused around the Victorian Central Highlands. A captive breeding program has since been developed at Healesville Sanctuary and is currently made up of six possums originally from the Yellingbo population – a genetically distinct population to that found in the Highlands. It is thought that there are now under 1000 individuals left in the Central Highlands area following the devastating 2009 bushfires and around 40 inhabiting the Yellingbo State Nature Conservation Reserve.
The Leadbeater's Possum is a beautiful and unique example of Victoria's faunal history. This new conservation status means that now more than ever do we as a state need to ensure the survival of this species, even in the face of natural disasters and habitat destruction. Hopefully, the high amount of publicity this critically endangered critter is receiving may ensure its protection into the future - although only time and the efforts of those involved will tell.
If you would like to learn more or get involved with the protection of the Leadbeater's Possum, follow the links below to a few of the relevant sites:
- Friends of Leadbeater's Possum
- Department of Environment and Primary Industries
- Great Forest National Park
- Species Profile, Department of the Environment