Macrotis is a genus of desert-dwelling marsupial omnivores known as bilbiesorrabbit-bandicoots;[3] they are members of the order Peramelemorphia. At the time of European colonisationofAustralia, there were two species. The lesser bilby became extinct in the 1950s; the greater bilby survives but remains endangered. It is currently listed as a vulnerable species. The greater bilby is on average 55 cm (22 in) long, excluding the tail, which is usually around 29 cm (11 in) long. Its fur is usually grey or white; it has a long, pointy nose and very long ears, hence the reference of its nickname to rabbits.
Macrotis means 'big-eared' (macro- + ōt- 'ear') in Greek, referring to the animal's large, long ears.[4]
The genus name was first proposed as a subgeneric classification, which after a century of taxonomic confusion was eventually stabilised as the accepted name in a 1932 revision by Ellis Troughton. In reviewing the systematic arrangement of the genus, Troughton recognised three species names, including one highly variable population with six subspecies.[5]
The family's current name Thylacomyidae is derived from an invalid synonymThylacomys, meaning 'pouched mouse', from the Ancient Greek thýlakos (θύλακος, 'pouch, sack') and mys (μῦς, 'mouse, muscle'),[3] sometimes misspelt Thalacomys.[6][7]
The placement of the population within taxonomic classification has changed in recent years. Vaughan (1978)[full citation needed] and Groves and Flannery (1990)[full citation needed] both placed this family[which?] within the family Peramelidae. Kirsch et al. (1997)[full citation needed] found them to be distinct from the species in Peroryctidae (which is now a subfamily in Peramelidae). McKenna and Bell (1997)[full citation needed] also placed it in Peramelidae, but as the sister of Chaeropus in the subfamily Chaeropodinae.[10]
Here is a summary of the treatment as a peramelemorph family:
Bilbies have the characteristic long bandicoot muzzle and very big ears that radiate heat. They are about 29–55 cm (11–22 in) long. Compared to bandicoots, they have a longer tail, bigger ears, and softer, silky fur. The size of their ears allows them to have better hearing.[13][14] They are nocturnal omnivores that do not need to drink water, as they obtain their moisture from food, which includes insects and their larvae, seeds, spiders, bulbs, fruit, fungi, and very small animals. Most food is found by digging or scratching in the soil, and using their very long tongues.
Unlike bandicoots, they are excellent burrowers and build extensive tunnel systems with their strong forelimbs and well-developed claws. A bilby typically makes a number of burrows within its home range, up to about a dozen, and moves between them, using them for shelter both from predators and the heat of the day. The female bilby's pouch faces backwards, which prevents the pouch from getting filled with dirt while she is digging.
Bilbies have a gestation of about 12–14 days, one of the shortest among mammals.[15]
The appearance of the bilby has been alluded to as "Australia’s answer to the Easter rabbit".[16]
Bilbies are slowly becoming endangered because of habitat loss and change, and competition with other animals. There is a national recovery plan being developed for saving them. This program includes captive breeding, monitoring populations, and reestablishing bilbies where they once lived. There have been reasonably successful moves to popularise the bilby as a native alternative to the Easter Bunny by selling chocolateEaster Bilbies (sometimes with a portion of the profits going to bilby protection and research). Reintroduction efforts have begun, with a successful reintroduction into the Arid Recovery Reserve in South Australia in 2000,[17][18] and a reintroduction into Currawinya National ParkinQueensland, where six bilbies were released into a predator-proof enclosure in April 2019.[19]
The bilby lineage extends back 15 million years.[25] In 2014 scientists found part of a 15-million-year-old fossilised jaw of a bilby which had shorter teeth that were probably used for eating forest fruit. Prior to this discovery, the oldest bilby fossil on record was 5 million years old. Modern bilbies have evolved to have long teeth used to dig holes in the desert to eat worms and insects.
It is thought the bilby diverged from its closest relative, an originally-carnivorous bandicoot, 20 million years ago.[26]
^"Thalacomys". Nomenclator Zoologicus Record. The Marine Biological Laboratory. Archived from the original on 1 January 2015. Retrieved 25 September 2014. err. pro Thyl- Owen 1838
^"Greater bilby". Department of Environment and Science – Queensland Government. 8 August 2003. Archived from the original on 23 April 2019. Retrieved 23 April 2019.
^"Bilby – Australia's Easter bunny". Environmental Protection Agency/Queensland Park and Wildlife Service. 24 November 2005. Archived from the original on 23 March 2006. Retrieved 23 April 2019.
