Macrotis

Macrotis
Bilby at Featherdale Wildlife Park
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Infraclass:	Marsupialia
Order:	Peramelemorphia
Family:	Thylacomyidae Bensley, 1903
Genus:	Macrotis Reid, 1837
Type species
Macrotis lagotis Reid, 1837[1]
Species
M. lagotis †M. leucura
Extant Macrotis distribution
Synonyms
Paragalia Gray, 1841 Peragale Lydekker, 1887 Phalacomys anon., 1854 Thalaconus Richardson, Dallas, Cobbold, Baird and White, 1862 Thylacomys Blyth, 1840[2]

Macrotis is a group (genus) of marsupials called bilbies or rabbit-bandicoots. They live in the desert and eat both plants and animals. They belong to a group called Peramelemorphia.

When Europeans came to Australia, there were two types of bilbies. The lesser bilby died out in the 1950s. The greater bilby is still alive but is in danger of disappearing. It is now called a vulnerable species. The greater bilby is about 55 cm (22 in) long, not counting its tail, which is about 29 cm (11 in) long. Its fur is usually grey or white. It has a long, pointy nose and very long ears, which is why it is sometimes called a rabbit.

The name Macrotis means "big-eared" in Greek, because the animal has big, long ears.^[3] The name was first used as a smaller group name but after many years of confusion, it became the official name in 1932 by Ellis Troughton. He found three species names, including one group with six smaller groups.^[4]

The family name Thylacomyidae comes from an old name Thylacomys, which means "pouched mouse" in Greek. Sometimes it is spelled Thalacomys by mistake.^[5][6]

The word bilby comes from the Yuwaalaraay Aboriginal language in northern New South Wales and means "long-nosed rat." In Western Australia, it is called dalgite, and in South Australia, some people call it pinkie.^[7] The Wiradjuri people of New South Wales also use the word "bilby."^[8] In 1864, Gerard Krefft wrote that people near the lower Darling River called it Jacko, later changed to Jecko, and near the lower Murray River, it was called Wuirrapur.^[4]

The way this group of animals is classified has changed in recent years. Vaughan (1978) and Groves and Flannery (1990) both put this family inside the family Peramelidae. Kirsch and others (1997) found that they are different from the species in Peroryctidae, which is now a smaller group inside Peramelidae. McKenna and Bell (1997) also placed them in Peramelidae, but said they are closely related to Chaeropus in a smaller group called Chaeropodinae.^[9] Here is a summary of how this family is treated as part of the peramelemorph group:

• Thylacomyidae
  • Genus †Bulbadon Travouillon, Beck & Case 2021
    • ?†B. warburtonae Travouillon, Beck & Case 2021
  • Genus †Ischnodon Stirton 1955
    • †I. australis Stirton 1955^[10]
  • Genus †Liyamayi Travouillon et al. 2014
    • †L. dayi Travouillon et al. 2014^[11]
  • Genus Macrotis (Reid 1837)
    • M. lagotis (Reid 1837) Jentink 1887 (Greater bilby)
    • †M. leucura (Thomas 1887) Iredale & Troughton 1934 (Lesser bilby)

Bilbies have a long nose like bandicoots and very big ears that help them stay cool. They are about 29–55 cm (11–22 inches) long. Compared to bandicoots, bilbies have longer tails, bigger ears, and softer, silky fur. Their big ears help them hear better.^[12][13] Bilbies are active at night and eat many kinds of food. They don’t need to drink water because they get moisture from their food, which includes insects, their larvae, seeds, spiders, bulbs, fruit, fungi, and very small animals. They find most food by digging or scratching the soil and use their long tongues to help.

Bilbies are great at digging burrows. They use their strong front legs and sharp claws to make long tunnels. A bilby usually has many burrows in its home area, sometimes up to 12, and moves between them. These burrows keep them safe from predators and the hot sun. Female bilbies have pouches that open backward, so dirt doesn’t get inside when they dig.

Bilbies have very short pregnancies, about 12–14 days, one of the shortest in mammals.^[14]

People sometimes call the bilby "Australia’s answer to the Easter rabbit" because of its appearance.^[15]

Bilbies are becoming endangered because their homes are being lost or changed, and because of competition from animals like foxes and cats. There is a national plan to help save them. This plan includes breeding bilbies in captivity, watching wild populations, and putting bilbies back where they used to live. People have tried to make bilbies popular by selling chocolate Easter Bilbies instead of Easter bunnies, with some money going to help protect bilbies.

There have been successful efforts to bring bilbies back to places like the Arid Recovery Reserve in South Australia (since 2000)^[16][17] and Currawinya National Park in Queensland, where six bilbies were released in a safe area in 2019.^[18]

Bilbies have also been reintroduced in Western Australia’s Peron Peninsula as part^[19] of the Western Shield program, and in other protected areas like the Australian Wildlife Conservancy’s Scotia^[20] Scotia^[21] and Yookamurra Sanctuaries.^[22] The Kanyana Wildlife Rehabilitation Centre^[23] near Perth runs a very successful bilby breeding program.

Bilbies have been around for about 15 million years.^[24] In 2014, scientists found part of a 15-million-year-old bilby jaw fossil. This old bilby had shorter teeth and probably ate forest fruit. Before this, the oldest bilby fossil was 5 million years old. Today’s bilbies have long teeth for digging in the desert to find worms and insects.

Scientists think bilbies split from their closest relative, a bandicoot that used to eat meat, about 20 million years ago.^[25]