Lesser Bilby
Encyclopedia
The Lesser Bilby also known as the Yallara, the Lesser Rabbit-eared Bandicoot or the White-tailed Rabbit-eared Bandicoot, was a rabbit-like marsupial
. The species was first described by Oldfield Thomas as "Peregale leucura" in 1887 from a single specimen from a collection of mammals of the British Museum
. Reaching the size of a young rabbit
, this species lived in the desert
s of Central Australia
. Since the 1950s-1960s, it has been believed to be extinct.
In modern times this species was endemic to the Gibson
and Great Sandy
deserts of arid central Australia and to northeast South Australia
and
adjoining southeast Northern Territory
in the northern half of the Lake Eyre Basin
.
It preferred to live in sandy and loamy deserts, sandplains and dunes covered with spinifex
, mulga, zygochloa canegrass
and/or tussock grass, as well as in triodia
hummock grassland with sparse low trees and shrubs.
It was an omnivore
feeding on ants, termites, roots, seeds, but it also hunted and fed on native rodents.
It burrowed in sand dunes, constructing burrows
2 – deep and closing the entrance with loose sand by day.
It is suggested that it may have bred non-seasonally and that giving birth to twins was the norm for this species.
Unlike its living relative the greater bilby
, the lesser bilby was described as aggressive and tenacious. Finlayson wrote that this animal was "fierce and intractable, and repulsed the most tactful attempts to handle them by repeated savage snapping bites and harsh hissing sounds".
The last specimen ever found was a skull picked up below a Wedge-tailed Eagle
's nest in 1967 at Steele Gap in the Simpson Desert, North West Territorry. The bones were estimated at being under 15 years old.
Indigenous Australian
oral tradition suggests that this species may have possibly survived into the 1960s.
The decline in numbers of the Lesser Bilby and ultimately its extinction was attributed to several different factors. The introductions of foreign predators like the cat and fox
, being hunted for food by native Australians, competition with rabbits for food, changes in the fire regime and the degradation of habitat have all been blamed for the extinction of this species. However Jane Thornback and Martin Jenkins suggested in their book that the vegetation in the main part of its range remained intact, with little evidence of cattle or rabbit grazing and point to cats and foxes as the most likely cause of the extinction of the lesser bilby
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
. The species was first described by Oldfield Thomas as "Peregale leucura" in 1887 from a single specimen from a collection of mammals of the British Museum
British Museum
The British Museum is a museum of human history and culture in London. Its collections, which number more than seven million objects, are amongst the largest and most comprehensive in the world and originate from all continents, illustrating and documenting the story of human culture from its...
. Reaching the size of a young rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
, this species lived in the desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
s of Central Australia
Central Australia
Central Australia/Alice Springs Region is one of the five regions in the Northern Territory. The term Central Australia is used to describe an area centred on Alice Springs in Australia. It is sometimes referred to as Centralia; likewise the people of the area are sometimes called Centralians...
. Since the 1950s-1960s, it has been believed to be extinct.
Description
The lesser bilby was a medium-sized marsupial with a body mass of 300 to 450 g (10.6 to 15.9 ). Its fur color ranged from pale yellowish-brown to grey-brown with pale white or yellowish-white fur on its belly, with white limbs and tail . The tail of this animal was long, about 70% of its total head-body length.Distribution and Habitat
Very little is known about its former range and distribution, as the species was collected only six times in modern history, with the first of these coming from an unknown region.In modern times this species was endemic to the Gibson
Gibson Desert
The Gibson Desert covers a large dry area in the state of Western Australia and is still largely in an almost "pristine" state. It is about in size, making it the 5th largest desert in Australia, after the Great Sandy, Great Victoria, Tanami and Simpson deserts.-Location and description:The Gibson...
and Great Sandy
Great Sandy Desert
The Great Sandy Desert is a desert located in the North West of Western Australia straddling the Pilbara and southern Kimberley regions. It is the second largest desert in Australia after the Great Victoria Desert and encompasses an area of...
deserts of arid central Australia and to northeast South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
and
adjoining southeast Northern Territory
Northern Territory
The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...
in the northern half of the Lake Eyre Basin
Lake Eyre Basin
The Lake Eyre basin is a drainage basin that covers just under one-sixth of all Australia. The Lake Eyre Basin is the largest endorheic basin in Australia and amongst the largest in the world, covering about 1,200,000 square kilometres, including much of inland Queensland, large portions of South...
.
It preferred to live in sandy and loamy deserts, sandplains and dunes covered with spinifex
Spinifex (genus)
Spinifex is a genus of perennial coastal grasses. They are one of the most common plants that grow in sand dunes along the coasts of Australia, New Zealand and New Caledonia.. As they help stabilise the sand, these grasses are an important part of the entire sand dune ecosystem. Of the four species...
, mulga, zygochloa canegrass
Zygochloa
Zygochloa is a monotypic genus of grass endemic to Australia. Its only species is Zygochloa paradoxa. It occurs in extremely arid areas such as the Simpson Desert.-References:*Watson, L., and Dallwitz, M.J. 1992 onwards...
and/or tussock grass, as well as in triodia
Triodia (plant genus)
Triodia is a large genus of hummock-forming grass endemic to Australia; they are commonly known as spinifex, although they are not a part of the coastal genus Spinifex. There are currently 64 recognised species...
hummock grassland with sparse low trees and shrubs.
Ecology and Behaviour
The lesser bilby, like its surviving relatives, was a strictly nocturnal animal.It was an omnivore
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
feeding on ants, termites, roots, seeds, but it also hunted and fed on native rodents.
It burrowed in sand dunes, constructing burrows
Burrows
Burrows is a provincial electoral division in the Canadian province of Manitoba. It was created by redistribution in 1957, and formally came into existence in the provincial election of 1958. The riding is located in the northern part of Winnipeg....
2 – deep and closing the entrance with loose sand by day.
It is suggested that it may have bred non-seasonally and that giving birth to twins was the norm for this species.
Unlike its living relative the greater bilby
Bilby
Bilbies are desert-dwelling marsupial omnivores; they are members of the order Peramelemorphia. Before European colonisation of Australia, there were two species. One became extinct in the 1950s; the other survives but remains endangered....
, the lesser bilby was described as aggressive and tenacious. Finlayson wrote that this animal was "fierce and intractable, and repulsed the most tactful attempts to handle them by repeated savage snapping bites and harsh hissing sounds".
Extinction
Since its discovery in 1887, the species was rarely seen or collected and remained relatively unknown to science. In 1931 Finlayson encountered many of them near Cooncherie Station, collecting 12 live specimens. Although according to Finlayson this animal was abundant in that area, these were the last Lesser Bilbies to be collected alive.The last specimen ever found was a skull picked up below a Wedge-tailed Eagle
Wedge-tailed Eagle
The Wedge-tailed Eagle , sometimes known as the Eaglehawk in its native range, is the largest bird of prey in Australia, but it is also found in southern New Guinea. It has long, fairly broad wings, fully feathered legs, and an unmistakable wedge-shaped tail...
's nest in 1967 at Steele Gap in the Simpson Desert, North West Territorry. The bones were estimated at being under 15 years old.
Indigenous Australian
Indigenous Australians
Indigenous Australians are the original inhabitants of the Australian continent and nearby islands. The Aboriginal Indigenous Australians migrated from the Indian continent around 75,000 to 100,000 years ago....
oral tradition suggests that this species may have possibly survived into the 1960s.
The decline in numbers of the Lesser Bilby and ultimately its extinction was attributed to several different factors. The introductions of foreign predators like the cat and fox
Red Fox
The red fox is the largest of the true foxes, as well as being the most geographically spread member of the Carnivora, being distributed across the entire northern hemisphere from the Arctic Circle to North Africa, Central America, and the steppes of Asia...
, being hunted for food by native Australians, competition with rabbits for food, changes in the fire regime and the degradation of habitat have all been blamed for the extinction of this species. However Jane Thornback and Martin Jenkins suggested in their book that the vegetation in the main part of its range remained intact, with little evidence of cattle or rabbit grazing and point to cats and foxes as the most likely cause of the extinction of the lesser bilby