Overview
The Greater Bilby (Macrotis lagotis), historically known in First Nations languages as the dalgyte, is a gentle, nocturnal bandicoot relative and one of Australia’s most culturally cherished desert marsupials. Renowned for its extraordinarily long, silky rabbit-like ears, shimmering blue-grey fur, and striking black-and-white crested tail, this charismatic creature once occupied over seventy percent of the Australian continent before suffering catastrophic historical range collapse following European settlement.
Ecologically, the greater bilby is a keystone ecosystem engineer across Australia’s fragile arid zones. By excavating dozens of deep, spiraling subterranean burrows and digging thousands of foraging pits each year, a single bilby turns over tons of compacted desert soil, trapping moisture, seeds, and organic matter that catalyze native plant germination. In contemporary Australian culture, it has achieved nationwide acclaim as the beloved ‘Easter Bilby’, a conservation icon championing native wildlife recovery over introduced invasive pests.
AT A GLANCE
- Common Name: Greater Bilby
- Scientific Name: Macrotis lagotis
- Category: Mammals
- Subcategory: Marsupials
- Size: Head-and-body length 29 to 55 cm (11.4 to 21.7 in); tail length 20 to 29 cm (7.9 to 11.4 in); males significantly larger than females
- Weight: 0.8 to 2.5 kg (1.8 to 5.5 lb) for adult males; 0.6 to 1.1 kg (1.3 to 2.4 lb) for females
- Lifespan: 6 to 11 years in the wild; up to 15 years in protected conservation sanctuaries
- Diet: Omnivorous opportunistic forager; subterranean beetle larvae, termites, ants, witchetty grubs, bush onion bulbs, grass seeds, and subterranean fungi
- Habitat: Spinifex grasslands, acacia shrublands, arid hummock grasslands, sand dune fields, and stony desert plains
- Range: Arid and semi-arid inland Australia, with surviving wild populations restricted to the Tanami Desert (NT), Great Sandy and Gibson Deserts (WA), and southwestern Queensland
- Conservation Status: Vulnerable (IUCN Red List)
Biology and Physical Characteristics
Macrotis lagotis possesses an extraordinary suite of arid morphological specializations. Its coat is composed of exceptionally soft, silky fur shaded in delicate ash-blue and dove-grey above, transitioning to a pure white underbelly. Its hallmark features are its immense, vascularized ears, which can reach up to two-thirds the length of its head; these colossal pinnae not only grant superhuman auditory detection of subterranean termite activity, but also circulate blood to dissipate metabolic body heat across scorching desert nights. Its long, tapered muzzle houses a keen olfactory system and sensitive vibrissae, while its robust forelimbs terminate in three heavily clawed central digits engineered for rapid, explosive earthmoving. Like many fossorial marsupials, the female bilby features a backward-opening pouch (marsupium), which prevents sand from smothering nursing joeys as the mother excavates deep trenches into desert sand dunes.
Behavior and Ecology
Strictly nocturnal and solitary, the greater bilby spends daytime hours resting deep inside subterranean spiral burrows that plunge up to two meters (6.5 feet) beneath the surface, maintaining a stable, humid microclimate that buffers against extreme desert surface heat. An individual bilby may maintain up to a dozen active burrows across its home range, switching between them to evade predators. At dusk, it emerges to forage across vast sandplains, using its sharp claws to dig conical foraging pits up to 25 cm deep in search of beetle larvae, root-boring moths, and grass seeds. Remarkably, bilbies do not need to drink standing water; they satisfy their entire moisture requirement metabolically from their insect and plant diet. Breeding is opportunistic and tied to rainfall; females possess one of the shortest mammalian gestation periods known, giving birth just 12 to 14 days after conception to tiny embryos that nurse in the pouch for 75 to 80 days.
Conservation and Human Impact
The Greater Bilby is classified as Vulnerable on the IUCN Red List (and Vulnerable under Australian national legislation), with its wild range reduced by over 80%. The catastrophic decline was precipitated by intense predation from introduced European red foxes and feral domestic cats, habitat destruction caused by sheep and cattle overgrazing, and severe competition for burrows and food from millions of invasive European rabbits. Intensive recovery operations—including predator-proof fenced reserves (such as Arid Recovery and Currawinya National Park), Indigenous Ranger tracking programs, and coordinated captive releases—are steadily stabilizing core populations.
Interesting Factoid
The Greater Bilby has a backward-opening pouch, an evolutionary engineering marvel that prevents dirt and abrasive desert sand from showering into the pouch and burying her babies while she digs deep underground burrows.