As we returned to Missouri yesterday, low, gray clouds shrouded the Great Plains and we knifed through banks of dense fog, drizzle and chilly rain on our route along Interstate 70. Such conditions kept most of the wildlife in their shelters but western kingbirds were especially numerous and conspicuous.
Summer residents of open country throughout the Western U.S. and the southern tier of the western Canadian Provinces, these attractive and aggressive birds have expanded their range over the past century and may be encountered east of the Mississippi River during migrations. Insectivores, they fly-catch from fenceposts, saplings and utility poles and also pounce on ground beetles, grasshoppers and other terrestrial prey; indeed, the latter seemed to be their primary means of hunting yesterday, when the raw weather may have nearly immobilized some of their victims. In my experience, western kingbirds are more opportunistic than their eastern cousins, often hanging out at truck stops to snare insects from the cattle carriers and light posts; while they generally nest in riparian woodlands, they also use human structures such as barns and windmill platforms.
Highly territorial, western kingbirds aggressively defend their nest area from a wide range of predators (real and imagined) and may raise two broods in southern latitudes. Come fall, they head for wintering grounds in Mexico, Central America and, in recent decades, South Florida.
