Western Kingbird Life History

Habitat

Western Kingbirds breed in open areas across western North America. Some of their preferred habitats include grasslands, desert shrub, savannah, pastures, cultivated fields, and urban land. Because they use trees and shrubs for nesting and open areas for foraging, Western Kingbirds often live near the edges of woodlands. They may be found near Fremont cottonwood, Arizona sycamore, oaks, junipers, creosote bush, mesquite, plains cottonwood, sagebrush, and ponderosa pine. They also perch and nest in human-made structures such as utility poles and fences. Western Kingbirds usually breed at elevations of less than 7,000 feet, in lowland areas or in mountain valleys. Most of them spend the winter in open woodlands, plantations, grasslands, and fields of southern Mexico and Central America.Back to top

Food

Like most other flycatchers, Western Kingbirds are mainly insectivores. They hunt by sight during the day, using acrobatic maneuvers to catch flying insects out of the air. A kingbird on the hunt may capture two or more insects before returning to its perch, where it shakes them or beats them against the perch to subdue them. Western Kingbirds also swoop down from perches to eat terrestrial prey, and glean insects from vegetation while hovering. Smaller-billed than most other North American kingbirds, they probably choose smaller prey. They eat bees and wasps, grasshoppers and crickets, beetles, moths and butterflies, caterpillars, flies, bugs, and spiders. On occasion they may eat fruits of elderberry, hawthorn, Texas mulberry, woodbine, and other shrubs. Back to top

Nesting

Nest Placement

Western Kingbirds build nests on crotches of trees or shrubs such as cottonwood, Texas mulberry, pecan, elm, willow, mesquite, creosote, yucca, sycamore, box elder, western juniper, big sagebrush, and green ash. They also use human-made structures such as utility poles, windmills, antennae, fenceposts, buildings, and metal girders. Both males and females visit potential nesting locations, but it’s unclear which one chooses the site.

Nest Description

The female builds the nest by herself, weaving together a bulky, open cup of grass stems, rootlets, fine twigs, cottonwood bark, cotton, and other plant fibers. She lines it with an inner layer of softer material such as wool, hair, feathers, string, or cloth. The nest measures about 6 inches across and 4 inches deep on the outside, while the inner cup is about 3 inches across and 2 inches deep.

Nesting Facts

Behavior

Males usually arrive at breeding areas before females and patrol the loosely defined borders of their territories. Once paired up, the male and female both help defend their territory, which shrinks as the breeding season progresses. By the middle of incubation the territory is quite small, consisting mainly of the nest tree and nest, but the pair defends it vigorously against other Western Kingbirds and other kingbird species. They even chase away larger predators, such as Red-tailed Hawks and American Kestrels, using a harsh buzzing call, snapping their bills, and raising their hidden red crown feathers. One of the biggest causes of nest failure is predation, despite the valiant efforts of the parents. Nest predators include snakes, squirrels, woodrats, owls, hawks, falcons, ravens, crows, magpies, and shrikes. Pairs mate monogamously, staying together to feed their young for up to three weeks after the young have fledged. They are mostly solitary throughout the rest of the year. Though Western Kingbirds tolerate neither closely related species nor predators in their territories, they may nest in the same tree as other birds such as Mourning Doves, Great-tailed and Common grackles, Bullock’s Orioles, Ash-throated Flycatchers, House Sparrows, American Robins, House Wrens, and Northern Flickers.Back to top

Conservation

Western Kingbirds are common, and populations remained fairly stable between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 30 million and rates them 9 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. Western Kingbird populations fluctuate on a local scale, decreasing when high predation or bad weather destroy nests but generally rebounding quickly in more favorable years. Western Kingbirds seem to benefit from many human activities, and their range has grown since the late 1800s. They have spread eastward across the prairies of the Dakotas as people planted trees and expanded across Texas as people cleared forests and installed utility poles and wires. Since Western Kingbirds nest near cultivated crops and often hunt for insects in farm fields, they may be harmed by pesticides.

Credits

Gamble, Lawrence R. and Timothy M. Bergin. (2012). Western Kingbird (Tyrannus verticalis), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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