The greater bilby, or simply bilby, (Macrotis lagotis) is a long-eared, rabbit-like mammal native to Australia. It lives in burrows and is active at night, feeding on insects, fruit, or fungi. The bilby is a marsupial and carries its young in a pouch. Threats include habitat loss, disease, and introduced predators such as foxes. Formerly widespread, bilbies are now restricted to arid parts of northwestern and central Australia.
It is commonly called bilby after the lesser bilby (Macrotis leucura) became extinct in the 1950s. Other names include dalgyte, pinkie, or rabbit-eared bandicoot.
Etymology and other names
The term bilby is a loan word from the Yuwaalaraay Aboriginal language of northern New South Wales, meaning long-nosed rat. It is also known as dalgyte in Western Australia by the Noongar people from their word djalkat. The Wiradjuri of New South Wales also call it bilby. Other names include pinkie and rabbit-eared bandicoot.
Taxonomy
Nomenclature
A scientific description of the greater bilby was first published in 1837 by a Mr J. Reid. Reid based his description on a specimen that he erroneously stated to have come from Van Diemen's Land (now Tasmania), where the species has not occurred in historical times. As all bandicoot species were then placed in a broadly circumscribed Perameles, Reid placed the bilby there too. However, noting how different it was from other members of the genus, he added that "should more of the same form be discovered, the above characters would constitute a subgenus to which the name of Macrotis might be applied". The specific epithet lagotis was chosen "from its resemblance to the Rabbit".
The following year, Richard Owen read a paper before the Zoological Society of London, in which he proposed to erect a new genus for this species, named Thylacomys. This name was widely adopted and remained in use for many years. Thus it was that when B. Arthur Bensley erected a subfamily to hold the genus in 1903, he named it Thylacomyinae. This name remains valid, and has since been promoted to family rank as Thylacomyidae, but Thylacomys itself is no longer considered valid, as Reid's original paper is held to have established the generic name Macrotis. Thus the currently accepted scientific name for the species is Macrotis lagotis.
Classification
The placement of bilbies within the Peramelemorphia has changed in recent years. Vaughan (1978) and Groves and Flannery (1990) both placed this family within the family Peramelidae. Kirsch et al. (1997) found them to be distinct from the species in Peroryctidae (which is now a subfamily in Peramelidae). McKenna and Bell (1997) also placed it in Peramelidae, but as the sister of Chaeropus in the subfamily Chaeropodinae.
Description
Greater bilbies have the characteristics of long bandicoot muzzle and very long ears. They are about in length. 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 as well. At , the male is about the same size as a rabbit; although male animals in good condition have been known to grow up to in captivity. The female is smaller, and weighs around . Bilbies have an excellent sense of smell and sharp hearing. Their fur is blue-grey with patches of tan and is very soft. The tail is black and white with a distinct crest.
Unlike bandicoots, they are excellent burrowers and can build extensive tunnel systems with their strong forelimbs and well-developed claws. A bilby typically makes several 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 backward, which prevents her pouch from getting filled with dirt while she is digging.
Ecology
Habitat
Once widespread in arid, semi-arid and relatively fertile areas covering 70 per cent of mainland Australia, by 1995 the bilby was restricted to arid regions and classed as a threatened species. Before the extreme contraction of its range to remote northern desert areas, the species was well known around Adelaide, especially in the city parklands, and it was also recorded as living around Perth.
It makes its home in a burrow that spirals down, making it hard for its predators to get in.
The bilby prefers arid habitats because of the spinifex grass and the acacia shrubs.