Bettongs

Also known as rat kangaroos. These small, nocturnal marsupials are only found in Australia and were once widespread.

Bettongs belong to the same family as potoroos and the now extinct Desert Rat-kangaroo.

There are five bettong species:

1. Eastern (or Tasmanian) Bettong (Bettongia gaimardi)
2. Burrowing Bettong (or Boodie) (B. lesueur)
3. Brush-tailed Bettong (or Woylie) (B. penicillata)
4. Northern Bettong (B. tropica), and
5. Rufous Bettong (Aepyprymnus rufescens).

Where do bettongs live?

All bettongs have suffered significant declines in their natural distribution following the expansion of agriculture and the introduction of feral predators such as cats and foxes.

In the 1920s, following the introduction of the Red Fox, the mainland population of the Eastern Bettong became extinct; the species is now restricted to Tasmanian, where its population has recently declined alarmingly, and a reintroduced population (inside a predator-proof fence) in the Australian Capital Territory. (1)

The Burrowing Bettong, once found across much of the central, southern and south-western Australia, is now extinct on the mainland (outside of predator-proof fences). It lives naturally on several islands off the coast of Western Australia, and has been introduced to more in South Australia. (2)

Similarly, the once-widespread Woylie is now extinct over much of its former range, persisting in intensively-baited remnant woodlands in south-west WA, and in predator-proof fences and a few offshore islands. (3)

The Northern Bettong is endemic to north-eastern Queensland, and is now known from only a small number of locations (critically, there are no captive or fenced populations of the Northern Bettong). (4)

The most common bettong is the Rufous, found along the east coast of Australia and abundant in Queensland.

The International Union for the Conservation of Nature (IUCN), lists the Woylie as Critically Endangered; the Northern Bettong as Endangered; the Tasmanian population of the Eastern Bettong and the Burrowing Bettong as Near Threatened; and the Rufous Bettong of Least Concern.

Depending on the species, bettongs can inhabit arid and semi-arid shrublands, spinifex grasslands, mallee shrublands, temperate woodlands and tall open forests with grassy understories.

Bettongs, like bandicoots, are important ecological engineers. Their digging plays an important role in decomposition of leaf litter (which reduces fuel loads and fire risk in dry grassy forests and woodlands) and in dispersing fungal spores and plant seeds.

Rufous Bettongs, for example, can travel 1.5km from their nest to feed – a large distance for a small mammal – spreading spores and seeds via their scats, snouts and paws as they move about the landscape.

Bettongs are able to reproduce at any time of the year. The Eastern Bettong’s gestation period is only three weeks long, and while it has only one young per litter, it can produce three young per year in favourable conditions. This relatively high rate of reproduction can lead to ‘extreme fluctuations’ in population, depending on rainfall and drought.

Threats to bettongs

Bettongs have faced and continue to face many threats. They have suffered from extensive loss of habitat due to land clearing for agriculture and development, and ongoing competition for food from stock and feral herbivores, including feral pigs, goats and rabbits.

The introduction of feral predators has been devastating for bettongs, which are particularly susceptible to foxes. Some species also face threats from changed fire regimes, affecting suitable habitat and food availability (e.g. truffles or particular grass species), which may be driven (in part) by the loss of bettongs (and other ground-foraging native species) from the ecosystem.