Saturday, May 21, 2016

Visitor from the Desert Southwest

On my usual birding walk at South Platte Park this morning, sightings were unremarkable except for a large number of yellow warblers and the presence of an ash-throated flycatcher.  The latter bird, rare along the Colorado Front Range, is a summer resident of the Desert Southwest, from western Colorado to California and from the northern Great Basin to Mexico.

Unlike most flycatchers, ash-throats generally snare their prey from foliage or directly on the ground; large insects, such as beetles and grasshoppers, are favored but they also consume berries and small lizards.  Nests are placed in the cavities of trees, fenceposts or nest boxes and two broods are raised each year.  Wandering widely during migrations, ash-throated flycatchers sometimes turn up on the East Coast; most winter in coastal regions of Mexico and Central America.

This morning's visitor was feeding on a wooded hillside, west of Eaglewatch Lake; on their home summer range, they are best found in pinyon-juniper or mesquite woodlands, along desert streams or in the canyons of desert ranges.  Adapting well to human habitation, ash-throated flycatchers are gradually expanding their territory and may soon be more common along the Front Range.