282 University of California Publications in Zoology [Vol. 24 



Similar lines of reasoning have been followed regarding other birds 

 than the waxwing ; that is, different types of plumage have been taken 

 as indicating different ages, rather than descriptions of plumages 

 being based upon specimens whose ages had been definitely ascer- 

 tained in other ways. There is probably hardly a species where it 

 would seem a more obvious or safer thing to do than to judge the 

 age of a waxwing from the number and size of the waxen wing tips, 

 yet inspection of the juvenal plumage shows how unsafe such assump- 

 tions may be. 



The most surprising statement in Cameron's account is the as- 

 sertion that "most birds had no red sealing wax appendages visible." 

 Of the forty-five adults examined in the present connection only one 

 lacks any trace of such an appendage, and except for Cameron's com- 

 ment I should have believed that it was unusual for a Bohemian wax- 

 wing to lack these ornaments. In the smaller cedar waxwing the case 

 is different. An examination of the latter species as represented in 

 this Museum discloses 36 specimens with more or less wax tips to the 

 secondaries, and 41 without a vestige of such marking. Judging from 

 the material at hand, therefore, this character seems to be much more 

 fully developed in Bombycilla garrula than in B. cedrorum. 



The fiocking instinct is strong in the waxwing at all times. The 

 nests we found, at two different localities, while not sufficiently close 

 together to merit the term "rookeries," were gathered in close prox- 

 imity, and to the exclusion of surrounding areas apparently just as 

 well adapted to the purpose. The birds obviously prefer to nest in 

 fairly close company. "When a sitting bird left the nest for the short 

 time necessary to feed each ^ay, it was to join one or two others and 

 do the foraging in company. While both birds of a mated pair work 

 at nest construction, apparently all the labor of incubation falls upon 

 the female. Her mate, thrown upon his own resources, usually joined 

 some other unoccupied male. Usually two males fed together; occa- 

 sionally there were more in company. Flocks were noted all through 

 the breeding season, usually of not more than twelve or fifteen indi- 

 viduals; by the end of July gatherings were seen that were several 

 times as large. 



In nest building, male and female worked together. Dixon (MS) 

 observed one pair at their labors for some time and made the follow- 

 ing notes : After the observer had taken his station the female arrived 

 with some white plant fiber. She put this fiber in place, and then, sit- 

 ting in the nest, she turned around and around, shaping thus, with her 

 breast, the nest cavity. Then the male arrived with more of the plant 



