Western mouse

The western mouse or walyadji, Pseudomys occidentalis, is a small, robust rodent of the family Muridae that once ranged across southwest Australia and into the arid interior but is now restricted to about ten reserves of remnant bushland and is rated near threatened. George Tate described it in 1951 from specimens obtained in 1930, with the holotype collected at Tambellup. It is about 10 centimetres long without the tail, which reaches 14 centimetres, weighs 30 to 55 grams and has soft, fine, dark grey and yellowish buff fur with black guard hairs, white feet, an aquiline nose profile and two pairs of inguinal teats. It digs burrows in loamy or sandy soil, each with a single entrance shaft and a looped tunnel network that up to ten individuals may share, and ventures out at night to forage nearby. It favours vegetation not burnt for decades, from open woodland to mallee and heath, and loss of habitat and climate change are expected to affect its numbers.