Brush-tailed Bettong

Bettongia ogilbyi is a species of potoroine marsupial that digs for fungi during the night, usually maintaining a solitary range around a central nest. The length of the head and body combined is 310 to 380 millimetres (12 to 15 in), entirely covered in fur that is a grey-brown over the back, a buff colour across the face, thigh and flank, and blending to the pale cream colour beneath. The greyish brown of the upper-parts of the pelage is interspersed with silvery hair. The tail is a similar length to the head and body, measuring from 290 to 350 mm (11 to 14 in), and is a rufous brown colour that ends in a blackish tip. The upper-side of the slightly prehensile tail has a ridge of longer fur along its length. The average measurements are 330 mm (13 in) for the heady-body length and 310 mm (12 in) for the tail. The average weight is 1,300 grams (46 oz). This species resembles the burrowing boodie (Bettongia lesueur), although the woylie is distinctly paler at the ventral side, and lacks the blackish colour of the boodie's tail. The ring around the eye of the woylie is pale, and its muzzle is longer and more pointed than the boodie, and less than Gilbert's potoroo (Potorous gilbertii), with which it once shared an overlapping distribution range.

The woylie is known to have once inhabited a wide range of habitats, including low arid scrub or desert spinifex grasslands. The population in south-west Australia persisted into the twentieth century, seemingly surviving the mass extinction of similar mammals in the previous decades, and was collected at temperate locations near Margaret River, by G. C. Shortridge in 1909, and by Charles M. Hoy in 1920. The last collections made at King George Sound and the Denmark regions of Western Australia in the 1930s coincided with the earliest records of the introduced red fox (Vulpes vulpes), which was first seen at Perth in 1927, and in the south not long thereafter. The dispersal of many potoroine species from their place of birth appears to be by sub-adult males acquiring a new territory. That has been recorded in these species when they reoccupy an area subjected to fire that had killed the previous residents.

Population collapse. The woylie was originally found in great abundance across southern Australia, north to about 30°S, in a wide distribution range from the coast in the west and east toward the Great Dividing Range. The species was observed at all parts of the Swan River Colony when the field worker John Gilbert visited during its founding years. …

As with the Potoroos and other Bettongia species, the woylie has a largely fungivorous diet and will dig for a wide variety of their fruiting bodies. Although it may eat tubers, seeds, insects, and resin exuded from Hakea laurina, the bulk of its nutrients are derived from underground fungi, which it digs out with its strong fore-claws. The fungi can only be digested indirectly. They are consumed by bacteria in a portion of its stomach. The bacteria produce the nutrients that are digested in the rest of the animal's stomach and small intestine. When it was widespread and abundant, the woylie probably played an important role in the dispersal of fungal spores within desert ecosystems. The austral summer and autumn seasons provide woylies with the fruiting bodies of hypogeous fungi, and around 24 fungal taxa are known to be consumed. During the summer months, species of the truffle-like Mesophellia form the major part of the diet. The core of the truffles of Mesophellia is consumed by woylies, which avoid the hard outer layer, and has been analysed for its nutritional value. The food is a rich source of lipids and trace elements accumulated by the fungus, and high protein levels that lack the required lycine and other amino acids, may be compensated by fermentation processes on the available aminos cysteine and methionine within the digestion. …