Northern bettong
Common name: northern bettong
Scientific name: Bettongia tropica (bettong = Aboriginal word for small wallaby, tropica = occurs in the tropics)
Family: Potoroidae (Potoroos and bettongs)
Conservation status: This species is listed as Endangered in Queensland (Nature Conservation Act 1992) and is Endangered nationally (Environment Protection and Biodiversity Conservation Act 1999). It is ranked as a critical priority under the Department of Environment and Resource Management Back on Track species prioritisation framework.
Description
The northern bettong is a delicately-built rat-kangaroo about the size of a rabbit with a body length between 300-380 mm and a tail length of 290-360 mm. An adult weighs between 1-1.5 kg. It has pale grey fur and a cream coloured belly. A short black brush of fur on top of the tail tip distinguishes it from the rufous bettong Aepyprymnus rufescens. The tail is prehensile and is used to carry nesting material. The northern bettong has a broad head with a flattened, naked nose and short, pointy ears.
Habitat and distribution
The northern bettong is endemic to Queensland's wet tropics. It has a small, fragmented distribution, occurring in upland grassy eucalypt woodland and tall open forest along the western edge of the Wet Tropics bioregion of north Queensland. The largest population occurs on the Lamb Range west of Cairns while two smaller populations persist near Paluma in the south and Mt Windsor in the north.
The northern bettong has a large home range of 20 ha or more, and territories can overlap. The climate profile for this species suggests it favours a mean annual rainfall of 1613 mm and a mean annual temperature range of 16-26 degrees Celsius.
Life history and behaviour
Truffles (fruiting bodies of underground fungi) and cockatoo grass Alloteropsis semialata appear to be the most important components of the northern bettong's diet. It also feeds on a wide range of foods including a number of other species of fungi, roots, tubers, seeds, insects, grass and leaves.
Northern bettongs are nocturnal, sleeping during the day in well-concealed nests constructed of grass, leaves and bark over shallow depressions or under thick shrubs or grass trees. When moving, they hop quickly with their head held low, back arched and the tail held straight out behind.
They are solitary animals that have three or four nest sites, which they use randomly. They are believed to become sexually mature at five or six months of age, and can breed at any time of the year, producing two to three litters of a single young. The gestation period is about 21 days and pouch life 110-115 days. Northern bettongs live for around six years.
Threatening processes
It is still uncertain what actual threats are impacting on the northern bettong. The most reasonable theory for bettong population declines is habitat modification resulting from altered fire regimes. This has resulted in thickening of their habitat with rainforest and Casuarina species and can affect the seasonal abundance and availability of their preferred food resources (truffles and cockatoo grass). Introduced predators such as cats and dogs also pose a considerable threat, along with resource competition from stray cattle and feral pigs.
Recovery actions
The main objectives outlined in the Recovery plan for the northern bettong (Bettongia tropica) 2000-2004 include:
- Maintaining and improving habitat for the northern bettong, particularly via suitable fire management practises.
- Improving our uderstanding of ecological factors such as interaction with introduced predators.
- Improving our understanding of species biology including genetics and disease research.
- Monitoring population trends across the species range, particularly the main population on the Lamb Range.
Last updated 5 December 2011