Greater bilby

Bilby - Australia's Easter bunny

Common name: greater bilby

Scientific name: Macrotis lagotis

Family: Peramelidae

Conservation status: This species is listed as Endangered in Queensland (Nature Conservation Act 1992) and is Vulnerable 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.

Among the hot, dry grasslands of western Queensland, the greater bilby lives far from the public interest surrounding its conservation. As one of Queensland's 16 Endangered mammals, the greater bilby is the subject of intense conservation efforts. This includes attempts to replace the Easter bunny with the Easter bilby in Queensland, to make the public aware of this important animal's plight.

• What does the greater bilby look like?
• Habitat and distribution
• Life history and behaviour
• What does the greater bilby eat?
• Threatening processes
• Recovery actions
• The Currawinya National Park bilby population
• How can you help?
• Related information

What does the greater bilby look like?

The greater bilby is the size of a rabbit, and has a long-pointed nose, silky pale blue-grey fur with a tan belly, big ears and a crested black and white tail. They measure up to 55 cm in body length, and their tail can be up to 29 cm long. Males weigh 1-2.5 kg, while females are lighter and weigh 800 g-1.1 kg.

These large ears are not for decoration, as they provide sharp hearing. This feature, combined with a strong sense of smell, is important for the bilby when looking for food. But all its senses aren't that effective because the bilby can't see very well. Interestingly when they run, they keep their nose down and this contributes to their unusual gait.

Habitat and distribution

The greater bilby once ranged over most of mainland Australia. But the arrival of exotic predators has eliminated bilbies from most of their former range. Its closest relative, the lesser bilby, is extinct.

For many years there were no records of bilbies in Queensland, and some thought that the species had gone extinct in the state. The then Queensland National Parks and Wildlife Service (QNPWS) surveys in Diamantina Shire between 1981 and 1985 failed to find any bilbies, although they did highlight suspected bilby habitats. It wasn’t until QNPWS focused more lengthy surveys on these suspected areas and historic sites that bilbies were rediscovered in 1988.

Now the greater bilby is found in a few places in western Queensland. Queensland's largest remaining group of bilbies lives in one area west of the Diamantina River in the State's far west, which includes populations in Astrebla Downs National Park and Diamantina National Park. Bilbies have also been re-introduced into Currawinya National Park. Across the rest of Australia, the greater bilby is restricted to parts of the Great Sandy, Gibson and Tanami deserts in central Australia and the Pilbara and west Kimberley in Western Australia. Bilbies have also been introduced to various sites in Western Australia and South Australia and to Scotia Reserve in New South Wales.

Bilbies can live in a range of habitats that include Mitchell grass plains, sandstone ridges, gibber plains, rocky soils with little ground cover, hummock and tussock grasslands, and Acacia shrublands.

Life history and behaviour

A powerful digger, the greater bilby makes spiral-shaped burrows up to three metres long and almost two metres deep. The reason they are so deep is to keep them safe from predators, and also to keep them at a constant temperature of 23 degrees Celsius. The bilby stays in its burrow during the day, looking for food well after dark. A bilby may have up to a dozen burrows—some for sleeping in and the others for escaping into. When returning to the burrow after a night of foraging, the bilby often back-fills the burrow to prevent predators from entering. The burrow contains no nesting material. A burrow takes a lot of energy to dig, but provides important protection, so bilbies will often repair and use old burrows. Some of these burrows could date back hundreds of years.

What does the greater bilby eat?

Bilbies are omnivores, which mean they feed on a range of foods including seeds, fungi, bulbs, and insects such as grasshoppers, beetles, spiders and termites. When looking for food, the bilby digs small holes up to 25 cm deep. These holes are scattered over bilby feeding areas.

The bilby has several distinctive features that it uses to find food. It uses its big ears and sharp sense of smell to find food, and it has a long, skinny tongue that it uses to lick up seeds from the ground. However, this feeding style means the bilby eats a lot of sand. In fact, 20-90 per cent of its faecal waste can be sand! Another feature is that it often eats the exoskeletons of insects, which shine in the light when their scat is broken open.

The bilby gets most of its water from its food rather than from drinking, which means it can survive in habitats without access to free standing water.

Bilbies live alone or in a pair. In the wild, the bilby lives to about seven years old, and they begin to breed when they are six months old.

The bilby is a prodigious breeder, and can produce up to eight young a year. Female bilbies usually give birth to two young, and as they can breed throughout the year, they can give birth up to four times per year. Female bilbies have an amazing short gestation period of just 12-14 days.

Like another endangered burrowing marsupial, the northern hairy-nosed wombat, female bilbies have a backward-opening pouch, which prevents soil entering the pouch when they are digging.

Young stay in the pouch for approximately 80 days, and then once they are out of the pouch they stay in their mother’s burrow for a couple of weeks. During this time their mother is very busy moving in and out of the burrow so that she can forage outside for food and return regularly to feed her young.

Threatening processes

As bilbies can live in a variety of habitats, eat a range of foods, survive without standing water, and breed rapidly, they should be more common then they are. So why isn’t the outback filled with bilbies?

In Queensland, the impact of predators such as foxes and cats has had the greatest effect on bilby numbers and continues to be the most serious problem.

The addition of artificial water points into the arid zone has contributed to the decline of bilby populations.  This has come about primarily as a result of exotic predators being able to roam over greater areas when provided with a access to additional permanent water. Bilby habitat fragmentation is also increasing, as a result of indirect competition for food with rabbits, and other factors such as changed fire patterns.

Recovery actions

The conservation of the bilby in Queensland will require providing adequate habitat where numbers of foxes and feral cats can be reduced and controlled, and where the other threats to bilbies can be managed.

A large part of the bilby's Mitchell grassland habitat in the Channel Country is now included in Astrebla Downs National Park, which will assist in protecting this important bilby population.

There is also ongoing research to better understand how bilby populations are changing over time. Broadscale low level, aerial surveys are conducted approximately every 5-10 years to assess burrow activity. Ground monitoring of burrow status is conducted annually in the Diamantina area.

The Currawinya National Park bilby population

Currawinya National Park is the only site in Queensland where bilbies have been re-introduced into the wild.

In order to prepare a site for the release of bilbies, a predator-proof fence was constructed in the Park, which encloses 29 square kilometres of habitat. This fence is of a special design, with tight mesh to prevent any predator from squeezing through, an outward-hanging top section to prevent cats from climbing over, and a buried skirt that prevents predators from burrowing in (and bilbies from burrowing out). Numerous people across Australia contributed to the Save the Bilby Fund, which provided the money to build the fence.

The completion of the fence in 2001 was followed by predator control to remove any foxes, cats and other animals that threaten bilbies from within the enclosed area. However, because of drought no bilbies could be released until December 2005.

With the arrival of rain in 2005, four bilbies—three females and a male—were released into the enclosure as a trial. The release was a success as within hours the bilbies had started to dig burrows and eat natural foods. This small population has been increased with further releases and natural breeding. Captive breeding for release into the Currawinya National Park enclosure is occurring at the Department of Environment and Resource Management (DERM) office at Charleville and on the Gold Coast at Dreamworld.

With significant rain events in recent years, and without the pressures of predation, the Currawinya population of bilbies has continued to expand and has given hope for future releases at other sites.

Response to a good season

Currawinya was inaccessible for some months after the floods but rangers have confirmed that the abundant conditions have led to some positive results for the bilby, with good numbers of young animals spotted.

At Astrebla Downs, the bilby population is also thriving but rangers are keeping a close watch on the current boom numbers of the native long-haired rat. Booms and busts of native animals, insects and plants are common after flood rains in Australia.

The booming rat population can also attract less welcome predators such as feral cats and wild dogs. The rats themselves have no impact on the bilby population. However, as their numbers decrease feral cats in particular can turn their attention to the bilbies as an alternative food source.

That’s why Queensland Parks and Wildlife Service rangers are keeping a close watch on the situation and are prepared to take action as part of the ongoing management of feral pests in national parks.

How can you help?

If you are in western Queensland and see a bilby in the wild, please report the sighting to the local DERM office.

You can also help the bilby and other Australian wildlife by supporting threatened species projects and caring for our native plants and animals. This will ensure our native animals survive where they belong in the bush.

Related information

Menkhorst, P and Knight, F 2001. A field guide to mammals of Australia. Oxford University Press, Melbourne, Victoria.

Pavey, C. (2006).National Recovery Plan for the Greater Bilby Macrotis lagotis (PDF, 407K)*. Northern Territory Department of Natural Resources, Environment and the Arts.

* Requires Adobe Reader

Last updated 11 October 2011

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