Western bluebird

The western bluebird (Sialia mexicana) is a small North American thrush.

The western bluebird is a small stocky bird with a length of 15 to 18 cm (5.9 to 7.1 in). The adult male is bright blue on top and on the throat with an orange breast and sides, a brownish patch on back, and a gray belly and undertail coverts. The adult female has a duller blue body, wings, and tail, a gray throat, a dull orange breast, and a gray belly and undertail coverts. Both sexes have a thin straight bill with a fairly short tail. Immature birds have duller colors than the adults, and have spots on their chest and back.

Their calling consists of the mating songs which sound like "cheer," "chur-chur," and "chup." This helps male western bluebirds find the females easily in condensed forest. The males use these calls to tell competing males that the territory belongs to them.

The western bluebird can be readily distinguished from the two other species in the bluebird genus. The western bluebird has a blue (male) or gray (female) throat, the eastern bluebird (Sialia sialis) has an orange throat, and the mountain bluebird (Sialia currucoides) lacks orange color anywhere on its body.