Northern bettong Photo: A Baker, NPRSR
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 Heritage Protection 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 (capable of grasping) 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
Northern bettong habitat Photo: A Baker, NPRSR
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. Northern bettong populations are fragmented from Mt Windsor Tableland (45 km NW of Mossman) in the north to Coane Range (65 km S of Ingham) in the south, representing a range of around 275 km. The Lamb Range (25 km SE of Mareeba) is the species stronghold, with a large population over a relatively broad area. Other populations appear to be small and cryptic, and are possibly declining. These include Mt Windsor, Mt Carbine, the greater Ravenshoe area, and Coane Range.
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 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 their tail held straight out behind them.
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.
Several threats are believed to affect the survival of northern bettongs. These threats continue to affect existing populations, compromising their persistence and limiting the likelihood of populations recovering to their former status. In order of perceived significance these are:
- changes to fire management which alter the preferred northern bettong habitat from open to closed forests
- feral pigs through competition for truffles and alteration of their habitat
- feral predators especially cats and foxes
- cattle grazing which alters to structure and composition of the understorey
- habitat clearing for agriculture, forestry and residential activities
- climate change leading to habitat alteration.
Northern bettong near trap at night Photo: A Baker, NPRSR
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 practices.
- Improving our understanding 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.
Curtis, LK, Dennis, AJ, McDonald, KR, Kyne, PM and Debus, SJS (eds) 2012, Queensland’s Threatened Animals, CSIRO Publishing, Collingwood.
Dennis, AJ 2001, Recovery plan for the northern bettong, Bettongia tropica 2000-2004, Report to Environment Australia, Canberra. Queensland Parks and Wildlife Service, Brisbane.
Johnson, CN and McIllwee, AP 1997, Ecology of the Northern Bettong Bettongia tropica, a Tropical Mycophagist, Wildlife Research 24, 549-559.
Johnson, PM 2003, Kangaroos of Queensland, Queensland Museum, Brisbane.
Winter, JW and Johnson, PM 2002, Northern bettong, in Strahan, R. (ed.), The Mammals of Australia, revised edition, Reed New Holland, Sydney.