The Creature Feature: 10 Fun Facts About the Bilby
Greater bilby. State of Queensland, via Wikimedia Commons.
Spring has arrived and the flowers are starting to bloom. ‘Tis the season for a certain long-eared mammal to hop its way into the spotlight. No, not the Easter Bunny. It’s time to celebrate the bilby!
The greater bilby (Macrotis lagotis) is an Australian marsupial about the size of a domestic cat. Thanks to its long, pinkish ears, it’s sometimes called the rabbit-eared bandicoot. Read on to discover what makes these critters unique and why some Australians are pushing for the bilby to replace the bunny as a symbol of Easter.
1. Bilbies are prolific and powerful burrowers. To keep cool and avoid predators, bilbies use their strong forelimbs and claws to build extensive tunnels. Each bilby may maintain up to 12 spiral-shaped burrows up to 3 meters (10 feet) long and 2 meters (6.5 feet) deep. They dig a new burrow every few weeks.
Bilbies aren’t the only ones taking refuge underground. Their burrows provide homes for dozens of other native animal species, including snakes, lizards, and other small mammals.
2. Bilbies are ecosystem engineers. As they build tunnels and forage for food underground, bilbies improve the soil health by turning over and mixing organic matter, increasing the nutrients available for plants to grow. One bilby can shift up to 3.6 metric tons of soil per kilogram of body mass in a year!
3. They poop sand. At night, bilbies emerge from their burrows to forage for food, which includes bulbs, tubers, seeds, insects and their larvae, worms, and spiders. Their feces are characterized by the exoskeletons of some of their prey, as well as dirt or sand that they ingest as they lick up seeds and other food from the ground.
Greater bilby. Sardaka, via Wikimedia Commons.
4. Their giant ears serve several purposes. Yes, those large, hairless ears are great for hearing potential prey and predators. But they also aid in thermoregulation, helping heat escape from the body. Bilby ears are exceptionally maneuverable. They can be rotated, flattened against the body, positioned at right angles, and even folded in half!
5. Bilbies have one of the shortest gestation periods. As marsupials, bilbies give birth to live young that continue their development in the mother’s pouch. After only 12—16 days post-breeding, females give birth to between one and three babies. These remain in their mother’s pouch for about 80 days.
6. They have pouches made for digging. Female bilbies have a backwards-facing pouch (the opening is located lower on the abdomen than the pouch itself). This prevents dirt from entering the pouch while they are digging.
7. Bilbies were once widespread. Bilbies can live in a wide range of habitats. Before the arrival of Europeans, they were found across more than 70% of Australia. Today, however, the only remaining wild populations are fragmented and restricted to a handful of remote, arid regions in Western Australia, Queensland, and the Northern Territory. The greater bilby is considered vulnerable to extinction.
8. They face big threats from non-native species. The demand for agricultural land has pushed bilbies into isolated pockets throughout Australia. Bilbies must compete for food and habitat with introduced species, such as rabbits, cattle, and sheep. Introduced predators, such as foxes and domestic cats, are another threat to bilby populations.
9. There were two bilby species. The greater bilby is commonly referred to simply as “the bilby,” but there was another bilby species not that long ago. The lesser bilby (Macrotis leucura) is thought to have gone extinct in the 1950s, due to loss of habitat and predation from introduced species.
Chocolate bilby. Nicole Kearney, via Wikimedia Commons.
10. The “Easter Bilby” is catching on in Australia. Bilbies compete with introduced European rabbits for food and habitat. In the 1990s, conservation groups such as the Foundation for Rabbit-Free Australia and Save the Bilby Fund started a campaign to promote the “Easter Bilby” as an alternative to the Easter Bunny in Australia. The idea is to raise public awareness of bilby conservation as well as educate about the ecological damage caused by introduced rabbits. Australians today can fill their Easter baskets with chocolate bilbies rather than chocolate bunnies!
References and Further Reading:
Australian Museum: Greater Bilby
Brown, E. 2011. "Macrotis lagotis,” Animal Diversity Web.
Bush Heritage Australia: Bilbies
Dawson, S.J., et al. 2019. An outback oasis: the ecological importance of bilby burrows. Journal of Zoology. Doi: 10.1111/jzo.12663.
Roth, A. 2019. “Meet the Bilby, Australia’s Own ‘Easter Bunny’,” National Geographic.
Taronga Conservation Society Australia: Bilby
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