The southern brown bandicoot (Isoodon obesulus) is a short-nosed bandicoot, a type of marsupial, found mostly in southern Australia. It is also known as the quenda in South Western Australia (from the Noongar word kwernt).
The fur of this bandicoot is coarse and coloured a dark greyish to yellowish brown, with the undersides a creamy-white. It has short, round ears.
The southern brown bandicoot shows some sexual dimorphism, with females being slightly smaller than males. The average male length is 330 mm (13 in), with a tail of 120 mm (4.7 in). Females are about 30 mm (1.2 in) shorter than the male, with a 10 mm (0.39 in) shorter tail. Males weigh an average of 0.9 kg (2.0 lb), females 0.7 kg (1.5 lb).
Reproduction is closely linked to local rainfall pattern, and many brown bandicoots breed all year around. A litter of up to five young is born after an eleven-day gestation period, and is weaned at two months.
The southern brown bandicoot is currently classified as Least Concern by theIUCN. However, populations have declined markedly and become much more fragmented in the time since European expansion on the Australian mainland. In many areas of its range the species is threatened locally, while it may be common where rainfall is high enough and vegetation cover is thick enough. Apart from habitat fragmentation, the species is under pressure from introduced predators such as the red fox and feral cats. It has been reintroduced to some lower rainfall areas where there is protection against cat and fox predation – one such site being Wadderin Sanctuary in the eastern wheatbelt of Western Australia, 300 km east of Perth.
In national assessment, the southern brown bandicoot is currently regarded as Endangered on the mainland as a whole, and Vulnerable in South Australia.