62 BREWSTER'S WARBLER. 



tracted period of song, early moult, and probable early migration would be the 

 natural concomitants of celibacy. 



On the 26th of June we found the second of the three male Golden-wings 

 feeding a brood of young in the Birch wood on one side of the swamp. This 

 male also, to our astonishment, had taken a Brewster's Warbler for a mate! 

 He could be readily distinguished at a glance from the first one by his 

 duller plumage, the white of the lower breast and belly being more heavily 

 tinged with ash. The young birds of this family were distinctly younger than 

 the other brood — by as much as three or four days, I should think. They were 

 also more numerous — five or six, apparently — and revealed more differences in 

 color than those that had been previously studied. The variations were espe- 

 cially obvious in the wing-bars which in some members of this family were of a 

 much paler yellow (almost white) than in others. On this day the young were 

 for the first time seen to make occasional flights into the lower branches of the 

 tall trees. On the 29th we observed that one of the little birds of this brood 

 (and so far as we could perceive, only one) had a triangular dusky area on the 

 throat and a similarly colored patch on each cheek, in short was a young 

 chrysoptera. 



A few days later the scope of our field study was enlarged by the discovery 

 of the whole family belonging to the third male Golden-wing that has been 

 already mentioned as occupying a station on the edge of the swamp in the early 

 summer. His mate proved to be a normal female Golden-wing and all the young 

 were Golden-wings, with dusky throats and cheeks. 



For the moment we were a little staggered as we thought of the complica- 

 tions that might arise from the presence of three broods within a comparatively 

 limited area; but we were delivered from confusion by one feature in the life 

 historj' of these birds: the integrity of the several families was absolutely main- 

 tained as long as the young were fed by their parents, and this condition en- 

 dured up to about the twentieth of July. 



The manner of making observations on these birds was as follows: On first 

 entering the precincts of the swamp I would listen intently for the voices of the 

 young birds. Their cricket-like chirping was incessant throughout the long 

 period in which they were fed by the old birds and fortunately their notes were 

 very characteristic and distinctive. The only sound in the swamp that could 

 be mistaken for the voices of the hungry little Helminthophilae was that emitted 

 by a young Cow-bird being fed by its foster-parents, a pair of Chestnut-sided 

 Warblers. The chirp of the young Helminthophilae also resembled in no 



