Brief SummaryRead full entry
Lesser bilby (Macrotis leucura)The lesser bilby, yallara or lesser white-tailed rabbit-eared bandicoot was collected only six times in modern history, with the first coming from an unknown region (15) and was very poorly known. In modern times it was endemic to sparsely vegetated sandy and loamy deserts, sandplains and dunes of 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 (13). It preferred habitats covered with spinifex, mulga, zygochloa canegrass and/or tussock grass and Triodia hummock grassland with sparse low trees and shrubs (9,13,16). It also lived in woodland, savannah and shrub grasslands (6). This rabbit-like marsupial was sexually dimorphic, with males larger than females. It is the size of a young rabbit. The body length of males is 365-440 mm, that of females is 320-390mm (3). The tail is 115-275 mm long and the weight is 300-450 g (13). The upper surface of the body is pale yellowish-brown to grey-brown or light grey and the underparts are yellowish-white or pale white with white limbs (13,14). The tail is white, with a gray line extending to the rear of the body (13,14). The bilby has very long, pointed, rabbit-like ears. The fore feet bear three stout toes with curved claws; the remaining two toes are very small. The hind feet have three toes. The first toe is made up of the fusion of digits 2 and 3, the second toe (digit 4) is very large, the last toe (digit 5) is an average size and the first digit is missing.
The lesser bilby was strictly nocturnal. It burrowed in sand dunes, constructing burrows 2–3 m deep and closed the entrance with loose sand by day. It was described as aggressive and tenacious. Finlayson (17) said it was "fierce and intractable and repulsed the most tactful attempts to handle them by repeated savage snapping bites and harsh hissing sounds". The bilby is omnivorous. It ate ants, termites, beetles, larvae and other small insects, as well as fruit, fungi and seeds (7,13,17). It also hunted and fed on native rodents (18). It does not need to drink water; it gets enough from fruit and seeds (8). Its desert habitat is harsh and when food is scarce, females resort to eating their young to survive (7). It may have bred non-seasonally (18) and that giving birth to twins was the normality for this species (17). The breeding season is March-May (4). 1-3 young are born after 21 days (6). The pouch opens downwards and backwards. The young stay attached to one of the mother's teats for 70-75 days while they suckle mother's nipples during that time. The young begin to be weaned 14 days after leaving the pouch (8). Mating occurs again 50 days after a litter is born (7).
Oldfield Thomas described the species as "Peregale leucura" in 1887 from a specimen in a collection of mammals in the British Museum (12). The Red List says this species is Extinct (7,9-11) and is CITS Appendix I. It has not been located since In 1931, when Finlayson encountered many of them near Cooncherie Stationin north-eastern South Australia. He collected 12 live specimens (1) and said the bilbies were abundant in that area (17). but these were the last lesser bilbies to be collected alive (2,7). The species has probably been extinct since the 1950s-1960s. A skull was found in 1967 in or below a wedge-tailed eagle's nest at Steele Gap in the Simpson Desert, North West Territory (1,2) The bones were estimated at being under 15 years old (4). Indigenous Australian oral tradition suggests that this species may have possibly survived into the 1960s (16). Aboriginal oral history suggests survival possibly into the 1960s (2), but there are no indications that it still persists. Hedley Findlayson said it was common (2) but it died out 35 years later after populations declined drastically due to trapping for its smooth, silky fur (8), changes in the fire regime, predation by introduced foxes and cats and competition with introduced rabbits for forage and burrows (7). Native Australians hunted the bilby for food (14). Some people have blamed habitat degradation (16), but Thornback and Jenkins (11)suggested that the vegetation in most of the bilby's range remained intact, with little evidence of cattle or rabbit grazing. They suggest that cats and foxes were the most likely cause of extinction (5). There are no conservation measures pertaining to this species.