Small macropod, 300-380mm in length, plus a tail length of 290-360mm. Yellowish grey above, paler on underside, has a black crest on the tail. Males and females are similar in appearance (Strahan, 1995).
Habitat and Distribution
As stated in the National Recovery Plan,
Habitat: Current habitat includes tall eucalypt forest and woodland, dense myrtaceous shrubland, kwongan (proteaceous) or mallee heath.
Present distribution: concentrated in the south west of Western Australia, however there are also a number of translocated populations as far north as Shark Bay and as far east as the New South Wales/ South Australian border.
As stated in the National Recovery Plan, the Brush-tailed Bettong is currently listed as critically endangered on the IUCN red list of threatened species.
Since 2001, populations have declined by as much as 95% to 99% in locations in the south west of Western Australia. As yet, there has been evidence of a decline in the abundance of individuals within populations but not a decline in the number of occurrences of the species. However, the Batalling Forest population (est of Collie, Western Australia) has been marginally detectable since 2007, having undergone a 99% decline since 2002.
The declines have occurred in most known large woylie populations and are not limited to Western Australia. A translocated population at Venus Bay (South Australia) suffered a dramatic crash in 2006 following a slow decline over the previous 12 months. This may have been a result of the restriction of emigration and subsequent resource limitation exacerbated by a series of six frosts. This suggests that the decline of this population may not be associated with the decline of the Western Australian populations.
Threatening processes likely to affect the brush-tailed bettong include predation by feral cats, predation by the European red fox, dieback caused by the root-rot fungus (Phytophthora cinnamomi), predation, habitat degradation, competition and disease transmission by feral pigs, land clearing and the loss of terrestrial climatic habitat caused by anthropogenic emissions of greenhouse gases.
Current Conservation Initiatives
A national recovery team for the woylie was re-established in 2008. There are a number of conservation initiatives for the woylie that are part of larger ongoing projects as well as more recent activities directed by the recovery team. These include:
- The management of introduced predators in areas occupied by woylies. Foxes and feral cats are managed in Western and Southern Australia through various management programs. The privately owned AWC Wildlife Sanctuaries, have fenced “introduced predator-free” environments on mainland Australia where woylies have been translocated.
|WA||Southwest WA via Western Shield fox control program||DEC|
|Wadderin Sanctuary||Shire of Narembeen|
|Private properties at Margaret River and Busselton||Private land owners|
- Translocation programs aim to increase the distribution of the species. These have been undertaken in Western Australia, South Australia and New South Wales primarily through the relevant state government conservation agencies but also involving Australian Wildlife Conservancy and private individuals/organisations (Figure 2).
- Investigation into the cause of the decline in the form of the Woylie Conservation Research Project. Phase 1 of the project, predominantly based in the Upper Warren region of Western Australia, has been completed and the results reported (see Wayne, 2008). The project was explorative in approach and aimed to diagnose the cause of the woylie declines. Phase 2 aims to investigate and scientifically test the most likely causes of the decline identified in Phase 1.
- Exploring the concept of mesopredator release. This is a major project undertaken by DEC’s Science Division, with input from Australian Wildlife Conservancy, and supported by the Invasive Animals Cooperative Research Centre. The project investigated the relationship between introduced predators (mostly foxes and cats) and various native species in 1080 baited and unbaited sites. The field component of this project is complete with analyses and write-up nearing completion (as at 2011).
As stated in the National Recovery Plan, a wide range of food types have been recorded including roots, tubers, leaf material, seasonal fruits/berries, bark and invertebrates. In southwest Western Australia, brush-tailed bettongs feed extensively on hypogeous fruiting bodies of ectomycorrhizal fungi. For captive diets please contact Perth Zoo.
Breeding and Lifecycle
As stated in the National Recovery Plan, woylies can breed continuously throughout the year and produce a single young at a time, though twins have been observed. Woylies exhibit embryonic diapauses, so it is possible for females to carry a blastocyst in the uterus, young in the pouch and have a young at heel. They have the potential to breed continuously, producing a maximum of three young per year. Gestation is 21.2 days and pouch life lasts for 90 days. Females are sexually mature by 6 months. The life expectancy is 4-6 years, though records show they can live up to 9 years in the wild and up to 14 years in captivity.
The Zoo and Aquarium Association acknowledges Perth Zoo for providing the factsheet information above.