COSTA'S HUMMINGBIRD 3G9 



the bees, by helping to transfer the pollen from stamens to pistil; 

 the bills and heads of hummingbii'ds are often smeared with pollen. 

 Behavior. — Quoting Mr. Woods (1924a) again: 



As the male Hummingbird takes no part or interest in the nest-building or 

 the rearing of the young, and a brief visit to any convenient flowers serves to 

 satisfy his appetite, he has considerable spare time at his disposal. Most of 

 this he spends on certain favorite observation posts, one of which is shown 

 in the photograph, whence he sallies forth occasionally in pursuit of a tres- 

 passing Hummer or bird of some other sort. Even the Cliff Swallow is not 

 immune from his attacks and seems quite unable to avoid his onslaughts. The 

 Hun)nungbird frequently mounts vertically into the air until almost out of 

 sight, then descends like a bullet directly at the object of his attention. If the 

 other bird flies, the Hummingbird follows ; if not, he passes within a few inches, 

 swet'ping through an arc which carries him upward again to repeat the process 

 until tired. The dowViWard swoop is accompanied by a long shrill whistle 

 which is characteristic of the species and is often the first indication of its 

 arrival in the spring. 



Elsewhere (1927b) he writes: "There is a remarkable difference in 

 the shyness of the various individuals when on the nest. Some will 

 leave as soon as a person comes into sight, perhaps forty feet away; 

 others will permit one to reach within a few inches, or possibly, with 

 care, even to touch them, without leaving the nest. The shyer ones, 

 however, are inclined to hold to the nest more closely as the incuba- 

 tion advances, and especially around the time of hatching. Most of 

 them, though easily frightened from the nest, will soon return if one 

 stands quietly a few feet away, a decided reversal of the tendencies 

 of the majority of nesting birds." 



A case of tameness, or curiosity, is reported by F. C. Lincoln 

 (1917) : "Mr. Figgins had an interesting experience with one of these 

 birds while sketching under his umbrella. The bird, a female, was 

 fearlessly curious and repeatedly came under the umbrella and 

 perched on the ribs, or the canvas, once flying so close to his face that 

 he (Mr. F.) forgetting the protection afforded by his glasses, shut 

 his eyes for fear the bird would strike at them." 



Hummingbirds seem to have few enemies. Perhaps they are too 

 small to attract birds of prey, or too active to be easily caught. But 

 accidents will happen occasionally. Mr. Woods (1934) reports find- 

 ing a bird of this species hopelessly entangled in a coarse, heavy 

 spider's w^eb; it was released with some difficulty and was at first 

 unable to fly away, but it finally recovered. 



Voiee. — Mr. Woods (1927b) remarks that "the presence of a Costa's 

 Hummingbird is frequently announced by the two-or-three-syllabled 

 whistling call with which he greets passing members of the tribe 

 from his perch or salutes his mate as he hovers before her. The 

 young males begin practicing on these whistling notes, which are 

 doubtless among the highest-pitched sounds audible to the human 



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