This week’s bird of the week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the western bluebird.
The western bluebird is a small thrush, about 7 inches long. It brings a beautiful flash of blue to Archuleta County, mainly in the summer and fall, usually in open fields and clearings in the forest. Adult males are 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. Adult females have a duller blue body, wings and tail than the male, a gray throat, a dull orange breast and a gray belly and undertail coverts.
Western bluebirds are highly social and usually feed in flocks during the nonbreeding season. They hunt for terrestrial insects by dropping to the ground from a low perch, sometimes hovering briefly before pouncing. Western bluebirds also frequently feed on berries in trees.
Western bluebirds rely on trees both for nesting cavities and hunting perches, and also perch on fences and utility lines. Western bluebirds nest in cavities, such as a natural hollow in oak or pine trees, old woodpecker holes, birdhouses and sometimes holes in a building. They usually nest fairly low, rarely up to 50 feet above the ground. The nest is probably built mostly by the female, but the male may take part. Their nest is a rather loose cup of twigs and weeds, lined with finer grass.
In recent decades, their numbers have declined over much of their range. Provision of birdhouses probably has not kept pace with loss of natural nest sites.
The western bluebird is sometimes mistaken for the mountain bluebird, which is also common in our area. The mountain bluebird is mostly blue all over its body without the orange, brown and gray patches of the western bluebird.
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