386 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



laid. Once the young bird is able to fly, however, the situation is 

 wholly changed, and the fledgling may look forward to the ex- 

 pectancy of a long life. If this were not true, the members of this 

 family could not have maintained their present abundance with their 

 small annual increase. The adult hummingbird seems to have no 

 enemies of importance; certainly no predatory bird could capture it 

 except by accident. On rare occasions a cat will catch one, in all 

 probability an immature individual that has not yet learned caution, 

 as seems to be generally the case among other birds. There are a few 

 accounts of disaster through the agency of an unintentional enemy, 

 such as the following from the manuscript notes of Carroll Dewilton 

 Scott: "On one occasion I rescued a female Amia from impending 

 death. A giant black spider had hung an enormous orb web among 

 pendant eucalyptus limbs about 8 feet from the ground. One spring 

 morning after a foggy night I noticed a female Anna fluttering on 

 the edge of the web. The spider was nowhere to be seen and had not 

 herself entangled the bird who had been snared, possibly, while gath- 

 ering webs for binding her nest. But she was hopelessly caught by 

 both wings in the tough, elastic, wet, sticky strands of the spider. 

 After I pulled the webs from her wings she flew to an adjoining 

 tree and sat quite still for several minutes." 



That these incidents happen so seldom is a tribute to the humming- 

 bird's alertness and quick perception, since the opportunities for such 

 mishaps are very numerous, and the webs of these large orb-weaving 

 spiders have been proved capable of holding considerably larger birds. 

 Mr. Scott also mentions finding a dead Anna's hummingbird at the 

 base of a window, presumably killed by striking the glass. Eric C. 

 Kinsey states, however, that hummingbirds kept in glass-sided cages 

 soon become accustomed to the glass and do not injure themselves 

 by flying against it. 



Of Anna's hummingbird, specifically, it would appear that the most 

 destructive enemy is the exceptional period of cold weather that comes 

 once in a cycle of years and, with native plants and animals alike, 

 may overcome the powers of resistance built up to withstand ordinary 

 winters. In this connection Mr. Dawson (1923) says: 



Hummingbirds, one sees, even though they be so frail, possess an amazing 

 vitality or recuperative power. But it is not too rare an experience to find one 

 stranded, or numbed with the cold; and, to cite the extreme instance, the big 

 freeze of January 2nd, 1913, undoubtedly cut down the resident hummer popu- 

 lation of southern California (all Annas) one-half. It is quite worth while 

 upon finding such a waif to try various methods of first-aid. The first expedient 

 is, of course, heat — that of the closed hand may suffice. Or, it may be that the 

 little engine only lacks "gas". Sweetened water, of a pretty strong solution, 

 offered in a pipette, or medicine dropper (pressed upon attention, or flooding 

 the bill until the tongue gets the flavor), will sometimes resuscitate a fallen 

 hummer like a magic potion. 



