Cassin’s Kingbird, Tyrannus vociferans

Cassin’s Kingbird, Tyrannus vociferans vociferans. Photograph taken in the greater Santa Ynez region of California, March 2011. Photograph courtesy of Dr. Tom Bartol, Carlsbad, California.

Cassin’s Kingbird, Tyrannus vociferans vociferans. Photograph taken within a residential community in Alamos, Sonora, April 2018. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

Cassin’s Kingbird, Tyrannus vociferans vociferans. Photograph taken within a residential community in Hereford, Arizona, June 2016. Photograph and identification courtesy of Bob Behrstock, Sierra Vista, Arizona (naturewideimages.com).

Background and Identification

The Cassin’s Kingbird, Tyrannus vociferans vociferans, is one of two subspecies of Cassin’s Kingbird, both of which are found in Mexico, and is a member of the Tyrannidae Family of Tyrant Flycatchers. There are thirteen global members of the Tyrannus Genus. They are known in Mexico as Tirano Gritón.

Cassin’s Kingbird is large in stature. The sexes are similar in appearance, which is known as sexual monomorphism. Plumages of males and females are maintained year-round. Heads of the Cassin’s Kingbird are a dark-gray with an orange-red patch on the crown, and they have a broad pointed bill with an ocular stripe. They have a white chin, a gray throat, and an upper breast and the remaining underparts are yellow. Their back is paler than the long wings, and the primaries are emarginated. Their tail is short and brownish-black. Their bill is black, their iris is dark brown and their legs and feet are black brownish-black.

Habitat and Geographical Range

Cassin’s Kingbird thrives in riparian zones, arid pine-oak woodlands, oak-scrub, thorn scrub, and thorn forests, typically at elevations between 700 m (2,300 feet) and 3,000 m (9,800 feet). This species is known for its noisy and conspicuous presence, displaying aggressive and dominant behavior, especially toward potential predators. Their diet consists of a diverse array of insects, as well as small berries and wild fruits. Breeding occurs in large trees within these arid riparian habitats, often at higher elevations than those of similar species. During the breeding season, the female is responsible for nest-building, incubating the eggs, and brooding the young, while the male remains nearby, keeping watch. Both parents share the responsibility of feeding the nestlings.

In Mexico, Cassin’s Kingbird is found in Baja California, and from western Sonora and Chihuahua south to Oaxaca. They are known to winter in Baja California Sur and Chiapas. The vociferans subspecies is widely found throughout Mexico in the states of Aguascalientes, Baja California, Baja California Sur, Chiapas, Chihuahua, Coahuila, Colima, Durango, Guanajuato, Guerrero, Hidalgo, Jalisco, México, Michoacán, Morelos, Nayarit, Nuevo León, Oaxaca, Puebla, San Luis Potosí, Sonora, Tamaulipas, Tlaxcala, Veracruz, and Zacatecas. Some populations of Cassin’s Kingbird are partial migrators, with individuals from northern Mexico wintering in southern Mexico. There are resident populations that exist in central and southern Mexico, and these groups do not migrate throughout the year. Common Misidentifications.

Common Misidentifications

Cassin’s Kingbird can be easily confused with Couch’s Kingbird, Tyrannus couchii. This species has a longer notched tail, in addition to a paler rump and back. Another species easily confused for the Cassin’s is the Thick-billed Kingbird, Tyrannus crassirostris. This species also has a larger and thicker bill. Two other species that may be confused are the Tropical Kingbird, Tyrannus melancholicus and the Western Kingbird, Tyrannus verticalis, which both have longer notched and black tails. The Tropical Kingbird is slightly larger and has a brighter belly and greener back, lacking the distinct white chin and throat of the Cassin’s Kingbird. It also has a more melodious song than the Cassin’s. The Western Kingbird is most well-known for the deep fork in its tail, a characteristic that the Cassin’s lacks.

Conservation Perspective

From a conservation perspective Cassin’s Kingbird is currently considered to be of Least Concern with stable, widely distributed populations. This bird is adaptable and has a wide range, which helps it maintain stable numbers despite potential threats.