About the Bilby

What does it look like?

The Greater Bilby is an iconic threatened marsupial. Bilbies are marsupial omnivores. They are members of the Peramelemorphia biological order and the largest of the bandicoots. Before European colonisation of Australia there were two species. One became extinct in the 1950s, the other survives but remains endangered.

Bilbies are about the size of a small cat and have soft, blue-grey fur with white underparts and a distinctive white-tipped tail. Bilbies have the characteristic long pointed bandicoot snout.

Image Courtesy Qld Parks and Wildlife

Bilbies' huge ears enable them to hear well even with their head down in the soil looking for food. They're also useful in thermoregulation.

As compared with other bandicoots, they have a longer tail, bigger ears, and softer, silky fur.

They are nocturnal omnivores that do not need to drink water, as they get all the moisture they need from their food, which includes insects and their larvae, seeds, spiders, bulbs, fruit, fungi and very small animals.

Most food is found by digging or scratching in the soil, and using their very long tongues.

Image Courtesy Alice Springs Desert Park

Where does it live?

Bilbies once inhabited 70% of Australia. In 1900 rabbit trappers near Adelaide would catch as many bilbies as rabbits. By the 1920's there were none to be found there.

The environmental changes of the last 200 years have resulted in a huge reduction in bilby habitat - damage done by feral foxes and cats; competition with rabbits and grazing animals; land clearing and degradation and changes to the traditional Aboriginal fire management have all had their toll.

The Greater Bilby (Macrotis lacotis) now only survives in scattered patches amongst the spinifex and mulga of the northern desert areas of Western Australia and the Northern Territory. A tiny isolated group of about 600 hangs on near Birdsville in Queensland.

Image Courtesy Erica Meles - Arid Recovery Project

The fate of their closest relative, the Lesser Bilby (M. leucura) is unknown. It was last seen alive over 70 years ago and is presumed to be extinct.

In the wild, bilbies are now limited to patches of the northern desert areas of NT and WA. and a tiny isolated remnant population in SW QLD. They are also found in sanctuaries and breeding colonies in WA, NSW, SA and QLD.

Most bilbies live in sandy desert areas in spinifex (Triodia species) grasslands. They dig large burrows up to 2 metres deep in sandplain country, where they live either singly or in pairs. They also seem to prefer freshly burnt country where there are more plentiful supplies of preferred foods.

They are excellent burrowers and build extensive tunnel systems with their strong forelimbs and well-developed claws. A bilby typically makes a number of burrows within its home range, up to about a dozen, and moves between them, using them for shelter both from predators and the heat of the day.

What does it eat?

Opportunistic omnivores, they dig for much of their food, feeding on whatever's around. out bulbs, seeds, fungi, fruit, grubs, termites, insects, spiders and lizards. If the tucker runs out, they're happy to move to where the grub's better. Their resilience even allows them to survive on termites in the height of droughts.

Bilbies do most of their foraging at night. They have sensitive noses which they use to sniff out their food which includes a mix of plant food (bulbs and seeds) and insects (termites, witchetty grubs and spiders), most of which they dig up with their strong front legs. One of the bilby's favourite plant foods is the bush onion or yalka (Cyperus bulbosa) that grows in desert sandplains after fires.

With huge rabbit ears and soft grey fur it's easy to see the resemblance to rabbits, but that's where it ends. Bilby ears are almost naked, which may be for temperature regulation, but because the research hasn't been done we don't actually know for sure.

Image right: courtesy Alice Springs Desert Park

"They look like they've been stuck together by a committee," says bilby conservationist, Tony Friend, "Huge ears that belong to a rabbit, soft grey fur, a tail that's stuck out the back like a tufted pencil and they gallop around like a rocking horse. They're so different to any other animals."

One thing that scientists studying bilbies do agree on is the variability in behaviour between bilby populations living in different conditions around Australia. They've adopted different diets, burrows, breeding habits and social networks, and this adaptability has been the key to their survival.

A useful trait for living in arid conditions is their ability to obtain all the water they need from food, which means that bilbies can get by without creeks or waterholes. Combined with their nocturnal lifestyle and deep burrows, their habits have allowed them to survive in arid areas, staying cool in summer and warm in winter, whilst avoiding many predators.

These cautious habits also make bilbies difficult to find and study in the wild. Only emerging in the dark, they stay close to any of a dozen or more burrows they may have in an area, ready to bolt down one if their sensitive ears detect a possible threat. They're also expert excavators, and if caught out in the open they can disappear from sight within three minutes in sandy soil.

In desert areas, bilbies often keep to themselves, digging simple burrows which spiral down up to two metres. Under more favourable conditions, they may live in larger loose groups with more complex warrens.Females tend to stay in a smallish area around their burrows, while males may wander a few kilometres at night, looking for a bit of "female company".

Opportunistic Breeders

Bilbies are opportunistic breeders waiting until conditions are good, rather than particular seasons. Females only come into season under good conditions which, in desert areas, depends on rain and food supply. In breeding colonies established in temperate areas they tend to adapt to seasonal patterns. And when the good times come, the bilbies make the most of them!

Image left: Courtesy Gulliver Media Australia Pty Ltd.

Image right: courtesy Diane Hunter / Kanyana Wildlife Refuge Service

"Bilbies are very good at sex," says June Butcher, from the Kanyana Wildlife Rehab Centre, who has bred over 70 bilbies. "Their mating sessions can last 18 hours."

The foetus develops quickly. A fortnight after mating the bean-sized newborn wriggles its way to the pouch. The pouch faces backwards, so it doesn't fill with dirt while mum's digging. When it first emerges 11 weeks later, the joey weighs around 200g.

Unlike other marsupials, baby bilbies rarely re-enter the pouch. The female has usually mated again, and the newborn bilby crawls into the pouch not long after the joey has left. "It wouldn't be good to have this hulking great thing damaging it trying to get into the pouch," explains Butcher.

However, the joey is not yet out on it's own, and is still fed by the mother. "The nipple that the joeys feed on actually hangs out of the pouch," says Butcher, "the one that the little ones latch onto inside the pouch produces a different quality of milk to the outside one that's feeding the young one at heel. It's pretty clever."

A few weeks later, the joeys are left to fend for themselves. Like many animals that produce young quickly to take advantage of good conditions, there's a fairly high attrition rate and only about 25% will survive to breeding age. Foxes and cats will account for many.

ARTICLE: Welcome to our newest baby Bilby ! Kanyana Wildlife Rehab Centre.