Greater Bilby Profile

34. Greater Bilby Profile

Common Name: Greater Bilby
Scientific Name: Macrotis lagotis
Genus: Macrotis
Family: Thylacomyidae
Order: Peramelemorphia
Class: Mammalia
Phylum: Chordata
Conservation Status: Vulnerable (IUCN)

Physical Description

The Greater Bilby is one of Australia's most beloved and iconic native mammals — a small, long-eared marsupial with a striking and immediately recognizable appearance that has made it a flagship species for Australian wildlife conservation. Soft, blue-grey fur, an extraordinarily long pointed snout, enormous bat-like ears, and a boldly bicolored tail of black and white distinguish it from any other Australian animal. In a continent renowned for its unique fauna, the Bilby stands apart as one of the most visually distinctive and evolutionarily ancient of all Australian marsupials.

Body Length: 29–55 cm
Tail Length: 20–29 cm
Weight: 0.8–2.5 kg (males significantly larger than females)

The Greater Bilby has a delicate, almost fragile appearance — fine silky fur, long slender limbs, and large translucent ears richly supplied with blood vessels that help dissipate heat in the desert environment. Its eyes are small and adapted for low-light vision, reflecting its nocturnal lifestyle. Its elongated, tapering snout houses a long, slender tongue used to extract insects, seeds, and fungi from soil and leaf litter with extraordinary precision. The hindlimbs are powerful relative to body size, used for rapid digging — a skill at which the Bilby is exceptionally accomplished.

Habitat

The Greater Bilby is a specialist of Australia's arid and semi-arid interior, though it once ranged across a far wider portion of the continent.

Primary Habitat: Arid and semi-arid grasslands, shrublands, mulga woodlands, and spinifex desert
Geographical Range: Now largely restricted to the Tanami Desert in the Northern Territory, the Gibson and Great Sandy Deserts in Western Australia, and parts of southwestern Queensland; formerly ranged across approximately 70% of the Australian continent

The dramatic contraction of its range — from over 70% of Australia's land area to a handful of isolated arid refuges — represents one of the most severe range collapses of any Australian mammal since European settlement. Bilbies require areas with loose, friable soils suitable for burrowing, sparse to moderate ground cover for foraging, and the absence or low density of introduced predators and competitors.

Diet

The Greater Bilby is an omnivore with a highly flexible diet shaped by the seasonal availability of food in its arid environment.

Primary Food: Bulbs, seeds, fungi, and plant material excavated from the soil
Additional Food: Insects and their larvae, spiders, small lizards, and other invertebrates

Bilbies are largely independent of standing water, obtaining the moisture they need almost entirely from their food — a critical adaptation for survival in the waterless interior of Australia. They forage by smell rather than sight, using their long snout and acute sense of olfaction to detect food items buried beneath the soil surface, then excavating them with their powerful forelimbs and sharp claws. Their diet shifts considerably across seasons, with fungi and bulbs dominating in wetter periods and invertebrates becoming more important during dry spells when plant material is scarce.

Behavior & Social Structure

Greater Bilbies are solitary, nocturnal animals with a shy and secretive nature.

Activity: Strictly nocturnal; retreats to its burrow well before dawn and does not emerge until after dark
Group Size: Solitary; males and females associate only briefly during the breeding season
Communication: Limited vocalizations; scent marking used to communicate territory and reproductive status

The Bilby is a prodigious burrower, constructing deep, spiraling burrows — typically 1–2 m deep with a corkscrew shape — that provide insulation from the extreme heat of the desert surface and protection from predators. A single individual may maintain up to a dozen burrows within its home range, rotating between them regularly. 

These burrows are critically important not just for the Bilby itself but for the broader desert ecosystem — abandoned Bilby burrows are used by a wide range of other animals including reptiles, small mammals, and invertebrates as shelter from the desert heat.

Reproduction

The Greater Bilby has one of the shortest gestation periods of any mammal, compensated by an extended period of development within the pouch.

Gestation Period: Approximately 12–14 days — one of the shortest of any mammal
Litter Size: 1–3 joeys, typically 1–2
Pouch Life: Approximately 75–80 days
Weaning Age: Approximately 165 days after birth

Like all marsupials, Bilby joeys are born at an extraordinarily early stage of development — tiny, hairless, and blind — and immediately crawl into the backward-facing pouch where they attach to a teat and continue developing. The backward orientation of the pouch is an adaptation to burrowing life, preventing soil from entering as the animal digs. Bilbies can breed year-round when conditions are favorable, with breeding activity typically peaking after rainfall events that boost food availability. Under good conditions a female can raise up to four litters per year, though in practice reproductive success is highly variable and heavily dependent on predator pressure and food availability.

Conservation Status

The Greater Bilby is classified as Vulnerable by the IUCN, with its population fragmented across a small number of isolated strongholds in Australia's arid interior. It is listed as Vulnerable under Australia's Environment Protection and Biodiversity Conservation Act.

Population Trend: Decreasing
Conservation Efforts: Predator-free fenced sanctuaries, captive breeding and reintroduction programs, invasive predator and competitor control, Indigenous ranger programs, community conservation initiatives, and the iconic Easter Bilby campaign that raises public awareness and funds for conservation

The Bilby has become one of the most prominent symbols of Australian wildlife conservation, widely recognized through the Easter Bilby initiative — a conservation-focused alternative to the Easter Bunny — that has raised significant public awareness and funding for Bilby recovery programs since its inception in the 1990s.

Did You Know?

• Alternative Easter Icon: The Greater Bilby is the subject of Australia's Easter Bilby campaign — a decades-long conservation initiative that promotes chocolate Bilbies as an Australian alternative to the Easter Bunny, with proceeds supporting the vital work of Bilby conservation. The campaign has been remarkably successful in raising both awareness and funds.

•  Corkscrew Burrows: Bilby burrows spiral downward in a corkscrew shape — a design that prevents predators from easily following the animal underground and maintains a stable, cool microclimate at the base even when surface temperatures soar above 40°C.

•  No Water Needed: Greater Bilbies obtain virtually all of the water they need from their food, making them entirely independent of standing water sources — a remarkable physiological adaptation to life in one of the world's driest environments.

•  Ecosystem Engineers: Bilbies turn over enormous quantities of soil through their burrowing and foraging activity — estimated at several tonnes per hectare per year — aerating and mixing the desert substrate and significantly influencing soil structure, nutrient cycling, and the germination of native plants.

Role in the Ecosystem

The Greater Bilby is one of Australia's most important native ecosystem engineers. Through its intensive burrowing and foraging activity, it turns over and aerates vast quantities of desert soil, creating conditions that promote seed germination, enhance water infiltration during rainfall, and cycle nutrients through the soil profile. Estimates suggest that a healthy Bilby population can turn over several tonnes of soil per hectare annually — a scale of disturbance that significantly influences the structure and productivity of desert plant communities. 

Their abandoned burrows provide critical shelter for a wide range of other desert species including reptiles, small mammals, insects, and birds, effectively creating habitat for the broader desert community. As seed dispersers and fungal spore spreaders through their foraging activity, Bilbies also contribute to the regeneration of native vegetation and the health of below-ground fungal networks that underpin desert plant communities. The loss of Bilbies from an ecosystem has measurable negative effects on soil health, plant diversity, and the availability of shelter for other species.

Why They're At Risk

The Greater Bilby's catastrophic range collapse — from over 70% of Australia to a handful of isolated desert refuges — is one of the starkest examples of the devastation wrought on Australian wildlife by European settlement. Introduced predators, particularly the red fox and feral cat, are the single greatest ongoing threat to Bilby survival. Both predators are highly efficient hunters of small ground-dwelling mammals and have driven the local extinction of Bilbies across vast areas of their former range. 

Introduced competitors — particularly rabbits, which compete directly for burrows and food, and livestock that degrade native vegetation through overgrazing — have compounded the impact of predation. Altered fire regimes, driven by the suppression of traditional Indigenous burning practices and the replacement of fine-scale mosaic burns with large, intense wildfires, have degraded the habitat structure that Bilbies depend on across parts of their range. 

Habitat clearance for pastoral development continues to reduce the area of suitable arid habitat available to the species. Despite the severity of these threats, the Bilby's story is not without hope — predator-free fenced sanctuaries across several states have established insurance populations, captive breeding programs maintain genetic diversity, and Indigenous ranger programs combining traditional ecological knowledge with modern conservation tools have produced meaningful results in parts of the species' remaining range.