Tyrannus verticalis

Geographic Range

Western kingbirds ( Tyrannus verticalis ) have a range that extends north to the southern parts of Canada and south to just beyond the border of the United States and Mexico. These birds are found as far east as the Mississippi River, however, they occasionally cross over into parts of Wisconsin and Illinois. Their western range stops shy of the Pacific coast. Populations of these birds are also known to winter in southern Florida.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Western kingbirds favor dry savannas, agricultural croplands, and riparian woodlands with scattered trees and shrubs. They prefer larger, taller trees with many perches available. Western kingbirds are also known to inhabit urban areas, making use of man-made structures such as utility poles and wires.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• savanna or grassland savanna or grassland
• scrub forest scrub forest

• Other Habitat Features
• urban urban
• agricultural agricultural

Physical Description

Western kingbirds are relatively large flycatchers. Adult males and females look the same with physical characters that include a small black bill, dark eyes, black legs and feet, and an orange-red central crown patch that is often hidden from view. They have an ashy gray head, neck, and breasts. Their lores are dark and their malar is white. Their coverts are dark and their back is a contrasting olive green. Their tail is black and square with white edges. Their belly and undertail coverts are bright yellow. Juveniles are similar in appearance, but are paler overall.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

Western kingbirds are monogamous and begin reproducing in late May to early June. Extreme cases have been reported into mid-July. In southern parts of their range, they begin constructing their nests in early May. Yet there are cases of nest building as late as the second week of July, most likely as a second attempt at nesting. Males perform a special courtship flight where they take off upward into the air, they flutter nearly in place, while vibrating their feathers and delivering a trilling song.

• Mating System
• monogamous monogamous

Western kingbirds prefer to nest in large trees and build cup nests placed 6 feet or more above the ground. They have also been known to use artificial structures for nesting such as telephone poles. When given the option, they choose to nest in cottonwood trees . More than one pair may nest in the same tree at any given time. Their nests consist of grasses, twigs, and weeds lined with finer materials such as hair or cotton. Nests are usually placed near the trunk on a horizontal limb. They have an average clutch size of 4, but depending on food availability, clutches may vary between 3 and 6 eggs. Their eggs are oval shaped and have an average weight of 3.83 grams. Eggs are brown or black with lavender spotting. Once the young hatch, they stay in the nest another 16 to 17 days. On average, western kingbirds produce 1 to 2 broods each year.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Among western kingbirds, both sexes contribute to nest building. The incubation is completed solely by the female and lasts about 18 to 19 days. Both males and females contribute to feeding.

• Parental Investment
• male parental care male parental care
• female parental care female parental care

Lifespan/Longevity

There is very little information available regarding the longevity of western kingbirds; however, they are believed to have a maximum lifespan of about 6 years.

Behavior

Western kingbirds are solitary but may sometimes be found in small pairs or groups, especially in the winter. They are known to be aggressive toward potential avian predators such as hawks, crows, and owls and chase them away from their nesting areas. Where nesting density is high, they take advantage by grouping together to ward off potential nest predators. As many as 10 individuals have been observed attacking as a group. Likewise, in one case, a western kingbird and a scissor-tailed flycatcher were observed simultaneously ganging up on a boat-tailed grackle that entered their nesting tree. Western kingbirds seem to tolerate similar species such as other kingbirds, despite their similar diets. Western kingbirds are a migratory species and disperse from their nesting areas in mid-August.

• Key Behaviors
• flies
• diurnal diurnal
• motile motile
• migratory migratory

Home Range

There is currently no data available regarding the home range size of western kingbirds.

Communication and Perception

Western kingbirds have a high, squeaky song, which sounds like "pidik pik pidik PEEKado". Their call is best described as a rapid and rising shrill, described as “widik pik widi pik pik”. They also have a sharp, hard “kit” call. In addition, these birds perform non-vocal behaviors when they perceive a threat, such behaviors include fluffing their crown feathers, fluttering or flicking their wings, and crouching.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Western kingbirds predominantly eat flying insects. These insects are relatively large compared to those eaten by other flycatcher species and include bees, robber flies, winged ants, and grasshoppers. In particular, one study showed the majority of their diet consists of insects from orders Coleoptera and Orthoptera . Western Kingbirds also consume fruits, berries, and arachnids . Fruits from buckthorn and sumac or poison ivy seeds are among their known food choices. These birds forage from open perches, which vary in height from low to high. When foraging in a riparian zone, they tend to perch higher than when they are in a desert landscape and they prefer flying insects less than 5 feet above ground. Western kingbirds spot prey from their perch and fly to catch it, usually returning to same perch afterward. They hover above their target and dip into the foliage or onto the ground to catch the prey. In one instance, they changed their foraging behavior to opportunistically feed on an abundance of tiger beetles on a pondside beach.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

• Animal Foods
• insects
• terrestrial non-insect arthropods

• Plant Foods
• seeds, grains, and nuts
• fruit

Predation

Predation causes up to 50% of nest losses. Cooper's hawks and Chihuahuan ravens are major nest predators. In response, western kingbirds are more aggressive toward these species than others. Unspecified falcons and owls have also been mentioned as nest predators. Open riparian nest sites suffer losses to predation more often than desert or forested riparian nests. There is no mention in the literature of adult birds being victims of predation.

Ecosystem Roles

Western kingbirds may help naturally control insects, feeding largely on flies, grasshoppers, and winged ants. These birds may also carry a variety of internal and external parasites.

Economic Importance for Humans: Positive

Western kingbirds may benefit humans by controlling insect populations.

Economic Importance for Humans: Negative

There are no known negative economic effects of this species.

Conservation Status

Western kingbirds are considered common and their population is stable and/or increasing. Currently, the IUCN states their population is increasing with a status of 'least concern'.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

Demetri Lafkas (author), Northern Michigan University, Alec Lindsay (editor), Northern Michigan University, Leila Siciliano Martina (editor), Texas State University.

References

Alsop, F. 2001. Birds of North America: Life Histories of More Than 930 Species . New York, NY: DK.

Barry, J., L. Butler, V. Rohwer, S. Rohwer. 2009. Documenting Molt-Migration in Western Kingbird ( Tyrannus verticalis ) Using Two Measures of Collecting Effort. The Auk , 126/2: 260-267.

Bergin, T. 1992. Habitat Selection by the Western Kingbird in Western Nebraska: A Hierarchical Analysis. The Condor , 94/4: 903-911.

Birdlife International, 2012. " Tyrannus verticalis " (On-line). IUCN Red List of Threatened Species. Version 2012.2. Accessed April 14, 2013 at http://www.iucnredlist.org/details/22700497/0 .

Blancher, P., R. Robertson. 1987. Effect of Food Supply on the Breeding Biology of Western Kingbirds. Ecology , 68/3: 723-732.

Blancher, P., R. Robertson. 1984. Resource Use by Sympatric Kingbirds. The Condor , 86/3: 305-313.

Gamble, L., T. Bergin. 2012. "Western kingbird ( Tyrannus verticalis )" (On-line). The Birds of North America Online. Accessed December 18, 2013 at http://bna.birds.cornell.edu.proxy.lib.umich.edu/bna/species/227/articles/conservation .

Hespenheide, H. 1964. Competition and the Genus Tyrannus . The Wilson Bulletin , 76/3: 265-281.

Johnston, D. 1971. Niche Relationships among Some Deciduous Forest Flycatchers. The Auk , 88/4: 796-804.

MacKenzie, D., S. Sealy. 1981. Nest Site Selection in Eastern and Western Kingbirds: A Multivariate Approach. The Condor , 83/4: 310-321.

Murphy, M. 1988. Comparative Reproductive Biology of Kingbirds ( Tyrannus SPP,) in Eastern Kansas. The Wilson Bulletin , 100/3: 357-376.

Ohlendorf, H. 1974. Competitive Relationships among Kingbirds ( Tyrannus ) in Trans-Pecos Texas. The Wilson Bulletin , 86/4: 357-373.

Schultz, T. 1983. Opportunistic Foraging of Western Kingbirds on Aggregations of Tiger Beetles. The Auk , 100/2: 496-497.

Sibley, D. 2000. The Sibley Guide to Birds . New York: Alfred A. Knopf.

Vuilleumier, F. 2011. American Museum of Natural History: Birds of North America Western Region . New York: DK Publishing.