360.

Western Mouse

Pseudomys occidentalis

French: Pseudomys occidental / German: Stumpfschnauzige Australienmaus / Spanish: Raton de Australia occidental

Other common names: \Walyadji, Western Pseudomys

Taxonomy. Pseudomys (Gyomys) occidentalis Tate, 1951, Tambellup, Western Australia, Australia.

In his 1951 description, G. H. H. Tate found P. occidentalis to be a member of the Gyomys subgenus. Early genetic data supported its placement in the Pseudomys genus. On morphological grounds P. occidentalis has been grouped with P. delicatulus, P. hermannsburgensis, P. novaehollandiae, P. albocinereus, and P. fumeus by C. H. S.

Watts and H. J. Aslin in 1981, but B. Breed and F. Ford in 2007 tentatively placed it in a subgroup with P. oralis . Monotypic.

Distribution. S Wheatbelt and coastal region ofSW Western Australia.

Descriptive notes. Head—body 85-110 mm, tail 120-140 mm, ear 19-20 mm, hindfoot 23-28 mm; weight 33-55 g. The Western Mouse is a medium-sized Pseudomys with gray dorsal pelage from which emerge dark and black guard hairs; ventral pelage is grayish white, and feet are white. Tail is bicolored, being gray above and white below, and longer than head-body length.

Habitat. The Western Mouse inhabits low shrubs and dense woodlands that have not been burnt for at least 15-50 years and have dense understory, generally occurring on sandy clay soils with alaterite component.

Food and Feeding. Western Mice feed on plant material and insects.

Breeding. Litter size is 4-5 embryos per female, usually born in early spring.

Activity patterns. Western Mice are terrestrial and nocturnal.

Movements, Home range and Social organization. There can be 1-7 ind/ha in suitable habitats. Communal nesting has been observed, and up to ten individuals can be found in a single burrow.

Status and Conservation. Classified as Least Concern on The IUCN Red List because of its distribution, its presence in various protected areas, and an apparent absence of major threats.

Bibliography. Breed & Ford (2007), Ford (2006), Tate (1951), Watts & Aslin (1981), Whisson (2008).