70 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



Colorado : 12 records, June 1 to 17. 

 South Dakota : 8 records, June 4 to 25. 

 Washington : 10 records. May 25 to June 20. 



TYRANNUS VOCIFERANS Swainson 



CASSIN'S KINGBIRD 



Plate 7 



Habits 



This is another yellow-breasted kingbird, somewhat resembling 

 the Arkansas kingbird and occupying some of the western, and more 

 especially southwestern, range of the latter. The range of vociferons 

 is not nearly so extensive as that of verticalis, and its local habitat is 

 often quite difl'erent. The two species are often found in the same 

 general habitat, especially during the migration periods, but during 

 the breeding season and to a certain extent at other seasons Cassin's 

 ranges higher in the foothills and the mountains than the Arkansas 

 kingbird. We found Cassin's kingbirds very common, in April and 

 May, in the lower portions of the canyons, among the large syca- 

 mores, in the Catalina and Huachuca Mountains in Arizona, Harr^^ 

 S, Swarth (1904), referring to the Huachucas, says: "I have occa- 

 sionally, but not often seen the birds as high as 7500 feet, and found 

 one nest quite at the mouth of the canyon, 4500 feet; but as a rule, 

 the territories occupied by this species and verticalis during the 

 breeding season hardly overlap," The majority of the nests he 

 found were between 5000 and 6000 feet. Referring to its range in 

 the Catalinas, W. E, D. Scott (1887) writes: "At the higher limits 

 of its range in the breeding season — about 9000 feet — it is much 

 more common than T. vet'ticaUs, though the reverse is true as re- 

 gards the lower limit of its range — about 3500 feet — in the breeding 

 season." Dr. Alexander Wetmore (1920) says that at Lake Burford. 

 N, Mex,, "they frequented rocky hillsides where scattered Yellow 

 Pines rising above the low undergrowth made convenient perches 

 from which to watch for insects and look out over the valleys." 



Henshaw (1875) found it frequenting open country' in Arizona 

 and New Mexico, saying, "I have seen it much on the sage brush 

 plains, though never very far from the vicinity of timber; and the 

 sides of open, brushy ravines seem to suit its nature well." 



In California, its distribution is more or less irregular, where it 

 seems to be less of a mountain species than in other places, for W. L. 

 Dawson (1923) says: "Cassin's Kingbird, at the nesting season, barely 

 exceeds the upper limit of the Lower Sonoran f aunal zone ; and it is 

 not even mentioned in the exhaustive reports on the San Jacinto and 

 San Bernardino mountain regions. It is apparently of very irregular 



