World Bird List

Species factsheet
Cassin's Kingbird (Tyrannus vociferans)

Order: Tyrannus vociferans
Family: Tyrant Flycatchers, Calyptura (Tyrannidae)

Voices can be found here (external link)
Subspecies and Distribution
Subspecie Distribution
vociferans sw USA to c Mexico
xenopterus sw Mexico
Annoncer