3G0 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



suspend the propeller motion of its winds, to furl them, to halve their normnl 

 .spread, and to resume again upon the other side of the screen. 



Voice. — Mr. Simmons (1925) tersely describes the vocal efforts of 

 this bird as follows : "Song, by male, a sweet and low, though very 

 high-pitched warble, like the sound produced as a result of whistling 

 through thQ teeth ; on still air, can be heard for 25 or 30 feet. Chase 

 note, similar to song, but louder and chippering, like a light and rapid 

 smacking of the lips together, uttered as one bird rapidly chases 

 another hither and thither." 



Mr. Woods (1927b) describes a courtship note as "a long-drawn, 

 pulsating, plaintive, liquid note, probably the most pleasing utterance 

 of any four Hummingbirds." 



Field marks. — The male black-chinned hummingbird is easily rec- 

 ognized by the black chin and sides of the head and by the conspicu- 

 ous white collar separating the square-cut gorget from the rather dark 

 imder parts ; the violet gorget, just below the black chin, is not easily 

 seen unless the light happens to strike it just right; there is a white 

 spot behind the eye, which can be seen at short range. The female is 

 not so easily recognized ; it is much like the female Anna's humming- 

 bird and is often seen with it, but it is decidedly smaller; the female 

 Costa's and female black-chinned are so much alike that they can be 

 distinguished only by a close view of the tail. In Costa's, according 

 to Ridgway (1911), the middle pair of rectrices are bronze-green, the 

 next pair similar, but with terminal portion black; third pair tipped 

 with dull white or pale brownish gray, extensively black subter- 

 minally and dull brownish gray basally, the gray and black separated 

 (at least on outer web) by more or less of metallic bronze-green; 

 fourth and outermost pairs with whitish tip broader, basal grayish 

 more extended, and with little if any metallic greenish between the 

 gray and black. In the black-chinned, the three outer rectrices on 

 each side are broadly tipped with white, the subterminal portion ex- 

 tensively black, the basal half (more or less) metallic bronze-green 

 (sometimes grayish basally). Thus, the comparative amount of 

 green on the two outer pairs of tail feathers determines the species. 



DISTRIBUTION 



Range. — Western North America. 



Breeding range. — The breeding range of the black-chinned hum- 

 mingbird extends north to southwestern British Columbia (probably 

 Brentwood, Chilliwack, probably Vaseaux Lake, and probably Edge- 

 wood) ; and probably northwestern Montana (Columbia Falls). East 

 to probably western Montana (Columbia Falls, Flathead Lalvc, Mis- 

 soula, and Stevensville) ; south-central Idaho (Blue Lake) ; western 

 Colorado (Glenwood Springs, Grand Junction, and Paradox) ; New 

 Mexico (Espanola, Roswell, and Carlsbad) ; and western Texas (San 



