The Western Rosella is the smallest rosella and is marked by a yellow or cream cheek patch. It occurs in southwestern Australia.
Males are mostly red on the head, neck, and underparts, with yellow to cream cheek patches. Females and juveniles have mottled red in those areas. The two subspecies differ in cheek-patch size and color, scalloping on the back, and the extent of red on the underparts.
It mainly eats seeds of grasses and other plants, along with fruit, flowers, insects, and their larvae. It feeds on the ground and in foliage, including in open grassy areas, and is usually seen in pairs or small parties.
It nests in hollows in branches or trunks, with wood dust at the bottom, and may also use hollow stumps or posts.
The female incubates the eggs and leaves the nest in the morning and late afternoon to be fed by the male.
An extinction-risk assessment has not been added yet.