^°19^"^^] TowNSEND, Status of Brewster s Warbler. 67 



Warbler, between Avhich and the Blue-winged Warbler there is a 

 complete series of intergrades. 



, (1) Although it has been objected that it would be impossible 

 to obtain a white-throated bird (leucobronchialis) from the inter- 

 breeding of a black-throated {chrysoptera) and a yellow-throated 

 bird (pinufi), yet I believe this is not the case, for in hybridization 

 secondary or less dominant characteristics may become latent. 



(2) The black throat of the Golden-winged Warbler is evidently 

 a secondary or late development, at first confined to the male. 

 The lesser development in the female, or its almost complete 

 absence as in specimen No. 1 would point in this direction, as 

 female birds are as a rule more ancestral or generalized in their 

 type. Specimen No. 2, although still retaining the ear patches 

 very faintly, shows a more complete reversion to the ancestral type, 

 although the suspicion of a black occular line may be taken to 

 mean Blue-winged blood. An occular line seems to be, however, 

 a more primitive decoration than the broader cheek patch of the 

 Golden-winged Warbler. Specimen No. 3 looked at from this 

 point of view shows a slight tendency to reversion, as half of the 

 throat has remained white. 



In the Redstart {Setophaga ruticilla) the very striking jet black 

 throat is attained by the male only, and that too not till the be- 

 ginning of the second year. The female and the young male both 

 have the simpler and more primitive light colored throat. If we 

 conld go back into the family history of this species, we should 

 doubtless find an ancestor where the male, instead of sporting the 

 brilliant flame and jet of the present bird, lived all his life a com- 

 paratively dull colored bird devoid of the black throat. It is 

 conceivable, although it can not be proved, that even at the present 

 day some male Redstarts live all their lives in the undeveloped or 

 ancestral white-throated stage. To make the analogy with speci- 

 men No. 3 still closer, it has only to be pointed out that young 

 male Redstarts sometimes show patches of the black on one 

 side only, before they attain their full development. A yearling 

 male Redstart in my collection (No. 638) taken at Stoneham, 

 Mass., on May 30, 1884, has a black patch three quarters of an inch 

 long and one eighth to one fourth inch wide, confined to the left 

 side of the breast. On the right side a suspicion of black is shown 



