420 LAND BIRDS 



of the alexandri is well worth watching. Should you 

 spy a male, swinging sidewise back and forth through 

 the air, pendulum fashion, look for the dainty little lady 

 on a twig about three feet in front of and a little above 

 him. So absorbed is she in watching and he in perform- 

 ing this curious aerial dance, that neither will notice 

 you. Sometimes at its finish he will drop exhausted on 

 any perch near and pay no further attention to her, but 

 oftener I have seen her dart out into the sunlight as 

 a signal for him to follow, and a merry chase through 

 the blossoms followed. Once, as he sat resting after his 

 graceful and apparently effortless swinging, the female 

 flew toward him, lit daintily a few inches away, and 

 quivered her iridescent wings. Instantly both birds 

 were in the air apparently engaged in a mortal combat, 

 and then he was back upon the perch like a flash of 

 light, while she had disappeared. I have never seen the 

 male Hummer assist at the nest building, and believe all 

 the family cares are left to the female. She is larger 

 and better equipped for labor than the brilliant little 

 sprite who wooes her. 



430. COSTA HUMMINGBIRD. — Calypte costw. 

 Family : The Hummingbirds. 



Length: Male 2.75-3.20 ; female 3.55-3.70. 



Adult Male .- Head and flaring ruff brilliantly burnished metallic ame- 

 thyst violet, changing to blue and green ; rest of upper parts bronze- 

 green ; under parts whitish ; belly washed with green. 



Adult Female: Upper parts bronzy green ; under parts whitish ; throat 

 spotted with metallic purple. 



Young: Similar to female, but duller and with feathers of the upper 

 parts margined with buffy. 



