Mammals
Greater Bilby
Macrotis lagotis · also called greater bilby, rabbit-eared bandicoot, dalgyte
The greater bilby is one of Australia’s most distinctive marsupials: a soft blue-grey animal with a long pink snout, a crested black-and-white tail, and a pair of enormous, hairless, rabbit-like ears. It spends the desert day underground and the night digging — and its abandoned burrows quietly keep a large part of the arid-zone wildlife alive.
Overview
Greater bilbies live in arid and semi-arid inland Australia, in spinifex grassland and shrubland with soil they can burrow into. Head and body run 30–55 cm, with a 20–29 cm tail that is black at the base and white-crested at the tip. They eat seeds, bulbs, underground fungi, termites, and grubs, and get all their water from food.
Built to dig
Powerful clawed forelimbs let a bilby excavate fast spiral burrows up to 3 m long and 2 m deep, and it makes and abandons many across its range. The female’s pouch opens backward so it does not fill with soil while she digs.
A fast breeder and an engineer
Gestation is only about 12–14 days, among the shortest of any mammal. Disused bilby burrows shelter reptiles, frogs, small mammals, and insects, and its foraging pits trap seeds and rainwater — which is why the bilby is called a desert ecosystem engineer.
Status
The greater bilby is Vulnerable and declining, gone from about 80 percent of its former range. Red foxes and feral cats are the main cause, with introduced rabbits, cattle grazing, and changed fire regimes adding pressure. It now survives in scattered wild populations plus fenced reserves and offshore islands. Since the 1990s the chocolate Easter Bilby has been sold in place of the Easter Bunny to fund its recovery.
Greater Bilby: common questions
Is a bilby a type of rabbit?
No. The greater bilby is a marsupial, a member of the bandicoot group, and it is not related to rabbits at all. It has large ears and lives in burrows, which is why it is sometimes called the rabbit-eared bandicoot, but it carries its young in a pouch, has a long pointed snout and a crested black-and-white tail, is a nocturnal omnivore that digs for food, and belongs to a lineage found only in Australia and New Guinea. The resemblance to a rabbit is superficial and is really just two burrowing animals with big ears.
Why does the bilby matter so much to the desert?
Because of its digging. A bilby excavates a large amount of soil every night, both for burrows and while foraging for bulbs, fungi, and grubs. Those disused burrows become homes for a long list of other animals that cannot dig their own, and the small foraging pits it leaves behind trap seeds, leaf litter, and rainwater, creating fertile spots where plants can establish. Where bilbies have vanished, that soil disturbance stops, and studies show the surrounding vegetation and the other burrowing wildlife suffer, which is why the bilby is described as an ecosystem engineer.
Why is the greater bilby endangered?
Mainly introduced predators and competitors. Red foxes and feral cats hunt bilbies across the arid zone and are the single biggest cause of decline. Introduced rabbits compete for food and burrows and degrade the vegetation, and grazing by cattle and changed fire patterns, since Aboriginal patch-burning largely stopped, have altered the habitat. The related lesser bilby has already gone extinct, in the mid twentieth century, and the greater bilby now survives in the wild only where these pressures are lower, along with populations behind predator-proof fences and on islands.
Where can you see a bilby?
Wild bilbies are nocturnal, shy, and live in remote desert, so they are very rarely seen by chance. The realistic options are to visit one of the fenced predator-free reserves or offshore island populations where they have been reintroduced and are monitored, or to see them in the nocturnal houses of Australian zoos and wildlife parks, several of which run captive-breeding programmes that supply animals for release. Some reserves offer guided night walks or spotlighting tours during which bilbies are occasionally encountered.