ANNA'S HUMMINGBIRD 371 



Egg dates. — California: 100 records, March 11 to June 29; 50 

 records, May 12 to June 10, indicating the height of the season. 



Baja California : 14 records, February 24 to June 5 ; 7 records, May 

 26 to 30. 



CALYPTE ANNA (Lesson) 

 ANNA'S HUMMINGBIRD 



PlATBJ 62 



HABITS 



Contributed bt Robebt S. Woods 



In two respects Anna's hummingbird occupies a unique place among 

 our hummingbirds. It is the only species the greater part of whose 

 general range is included within a single State of the Union, and 

 the only one that winters mainly within the United States. It is 

 also the species most familiar to residents of California, since its 

 territory includes all the more populous districts of the State, where 

 it is a constant and by no means shy visitor to city parks and gardens. 

 Anna's hummingbird seems to be in some degree nomadic in its habits, 

 and it probably shifts slightly southward during the colder months, 

 but it performs no true migration, thereby differing from all our 

 other species except that portion or race of Allen's hummingbird 

 resident on the Channel Islands of southern California. 



Courtship. — In April, in the blooming orange groves of southern 

 California, at least five of the six species of hummingbirds regularly 

 occurring in that region may sometimes be seen together, in consid- 

 erable numbers and feverish activity. No small part of that activity 

 consists in the practicing of higlily specialized forms of courtship 

 flight. While the males of all California hummingbirds can easily 

 be recognized when clearly seen, identification is more difficult when 

 the bird persists in manifesting itself as a vague streak rather than a 

 definite object. Under these circumstances a knowledge of the specific 

 distinctions in "nuptial flight," and particularly of the peculiar and 

 entirely characteristic utterances accompanying such flight, is often 

 of great assistance in determining species. 



The most elaborate of these nuptial flights is that of Anna's hum 

 mingbird, in which the bird mounts upward until almost lost to sight 

 then shoots vertically downward at tremendous speed, finally alter- 

 ing his course to describe an arc of a vertical circle, which carries him 

 as closely as possible past the object of his attention as she sits 

 quietly in some bush or tree. At the lowest point of the circuit he 

 gives utterance to a loud, explosive chirp, which so nearly resembles 

 the "bark" of a California ground squirrel {Gitellus heecheyi) that 



