The Cassin's kingbird, known scientifically as Tyrannus vociferans, is a robust member of the tyrant flycatcher family. This species is a living tribute to the American ornithologist John Cassin, whose name it bears. Adults are characterized by a gray head with marginally darker cheeks and a dark, unforked tail edged with a buffy fringe. The underparts are a subtle gray-olive, while the throat is pale, transitioning to a vibrant yellow on the lower breast.
When identifying the Cassin's kingbird, look for its length of 8.3–9.1 inches and a wingspan of approximately 41 cm. Juveniles present a duller appearance with pale wing edges. Notably, this species can be distinguished from similar birds by its tail pattern—a thin white edge at the distal end of the tail feathers.
Cassin's kingbirds favor rangelands and savannas, where they can be observed perched in mid-story or canopy levels of trees.
During the summer months, these birds grace the skies of California, stretching from Montana to Utah along the eastern Rocky Mountains. They migrate to winter habitats ranging from Southern California to northern Central America, with permanent populations residing in south-central Mexico.
These kingbirds are known for constructing bulky nests on horizontal tree limbs. They exhibit a fascinating mating ritual in early spring, where pairs hover in unison with outstretched wings, performing a dance over selected perches. This ritual is repeated multiple times over several days and across various sites.
The Cassin's kingbird communicates with a distinctive call, a high-pitched chirp that can be described as "chi-beer," with a shorter note followed by a longer one.
The breeding process involves laying three to five spotted white eggs, which undergo an incubation period of 18 to 19 days.
The western kingbird is often mistaken for the Cassin's kingbird. However, the Cassin's is slightly larger, with darker gray upper parts and a distinctive tail pattern compared to the western kingbird.
Insects are the primary diet of the Cassin's kingbird, which it catches in flight from high perches—a behavior known as hawking. Berries and fruits are also consumed, albeit in smaller quantities.
The Cassin's kingbird is currently listed as Least Concern on the IUCN Red List, indicating a stable population without immediate threats to its survival.