The bilby, a marsupial native to Australia, is recognized by its long ears, pointed snout, and strong claws. It is a nocturnal burrowing animal, able to dig spiral burrows up to 3 meters long and 2 meters deep, which provide shelter from heat and predators. Once widespread across 70% of the Australian mainland, the greater bilby (Macrotis lagotis) is now listed as vulnerable nationally and endangered in Queensland. The lesser bilby (Macrotis leucura), a close relative, is believed to have become extinct in the 1950s.
Shrinking Natural Spaces
Human activities have reduced and fragmented bilby habitats across Australia. Land clearing for agriculture, urban development, and mining operations directly destroy the ecosystems bilbies rely on. Mining projects, for instance, can lead to habitat loss.
Habitat degradation also results from altered fire regimes, including frequent, intense fires that destroy vegetation cover and food sources. Infrastructure development, such as roads and railways, further fragments habitats and can lead to bilby mortality through vehicle collisions. These combined pressures have contracted the bilby’s range to less than 20% of its former distribution.
Threat from Introduced Animals
Introduced predators pose a major threat to bilby populations. Feral cats (Felis catus) and red foxes (Vulpes vulpes) are efficient hunters that have contributed to the decline of native Australian mammals. Red foxes, introduced for hunting, have spread across most of Australia.
Bilbies are particularly vulnerable to these predators because they evolved without such threats, lacking effective defenses. Their burrowing behavior, while offering some protection, does not completely safeguard them from these persistent hunters. Predation by feral cats is considered the greatest threat to Australia’s terrestrial mammals, having contributed to the extinction of numerous species and threatening many more.
Competition for Survival
Other introduced species compete with bilbies for resources. European rabbits (Oryctolagus cuniculus) directly compete with bilbies for food, such as grasses and seeds, and for burrows. Rabbits can also eject bilbies from their burrows.
Large rabbit populations also support higher numbers of feral cats and foxes, intensifying predation pressure on bilbies. Grazing livestock, including cattle and sheep, also degrade bilby habitats through overgrazing and trampling, reducing the availability of food plants and altering the landscape. This competition further strains bilby populations already struggling with reduced natural spaces.
Changing Environmental Conditions
Climate change introduces pressures on bilby populations through altered environmental conditions. Increased frequency and intensity of droughts limit food and water availability. Extreme heat events and altered rainfall patterns can lead to reduced vegetation cover, exacerbating scarcity.
More frequent and intense bushfires, often linked to changing climate, destroy large areas of bilby habitat. These fires remove cover, making bilbies more susceptible to predation. Such environmental shifts can further reduce available resources and increase vulnerability to other threats.
Efforts to Protect Bilbies
Various conservation strategies are underway to protect bilbies and help their populations recover. A key approach involves establishing fenced, predator-free exclosures, or sanctuaries, where bilbies can live and breed without the threat of introduced predators. Reintroduction programs are also conducted, releasing captive-bred bilbies into suitable habitats, including these protected areas.
Intensive predator control measures, such as trapping and baiting, are implemented outside of exclosures to manage feral cat and fox populations. Captive breeding programs are important in increasing bilby numbers and maintaining genetic diversity, with individuals transferred between facilities to ensure healthy populations. Community awareness campaigns, including the “Easter Bilby” initiative, aim to educate the public and raise funds for conservation. Collaboration with Indigenous land managers is also important, as traditional ecological knowledge and land management practices contribute to bilby persistence, with about 70% of current bilby populations residing on Indigenous lands.