Tyrant-flycatchers (Tyrannidae)

Cassin's Kingbird (Tyrannus vociferans) - HBW 9, p. 421

French: Tyran de Cassin German: Cassinkönigstyrann Spanish: Tirano Gritón

Taxonomy: Tyrannus vociferans Swainson, 1826, Temascáltepec, Mexico.
Closest relatives of genus may be Empidonomus and Tyrannopsis; recent molecular-sequence data indicate present genus is monophyletic and sister-group to clade that includes Empidonomus and Griseotyrannus; two main clades within genus, loosely corresponding to “tropical species assemblage” and combination of “W” & “E” species groups of earlier authors, but with some exceptions. Phylogenetic analyses indicate that present species is basal to a clade including T. verticalis and T. forficatus within an “E & W species group” that al.. View all taxonomy...

Taxonomy: Tyrannus vociferans Swainson, 1826, Temascáltepec, Mexico.
Closest relatives of genus may be Empidonomus and Tyrannopsis; recent molecular-sequence data indicate present genus is monophyletic and sister-group to clade that includes Empidonomus and Griseotyrannus; two main clades within genus, loosely corresponding to “tropical species assemblage” and combination of “W” & “E” species groups of earlier authors, but with some exceptions. Phylogenetic analyses indicate that present species is basal to a clade including T. verticalis and T. forficatus within an “E & W species group” that also includes T. tyrannus and perhaps T. caudifasciatus and/or T. cubensis. On basis of similarities in voice and some aspects of behaviour, may be closest to T. couchii, T. crassirostris and T. verticalis, but this not yet supported by molecular data. Validity of race xenopterus questionable; further investigation necessary. Two subspecies tentatively recognized.

Subspecies and Distribution:

  • vociferans Swainson, 1826 - W & C USA (SE Montana, E Wyoming, SW South Dakota, SW Nebraska, C & S California, extreme SE Nevada, S Utah, SW & SC Colorado, N & E Arizona, New Mexico, W Texas), Mexico (Baja California, and S from W Sonora and Chihuahua to Oaxaca and Chiapas) and Guatemala.
  • xenopterus Griscom, 1934 - SW Mexico (highlands of Guerrero).