^°1908^^] Porter, Nesting Habits of Birds in the Spring of 1907. 19 



location, the construction of the nest, the appearance of the eggs, 

 the appearance and actions of the birds, I beUeve to be a second 

 set of the nest of June 8. Mr. Hoyt took this set June 22, with 

 four eggs, and incubation four or five days advanced. 



With this species the authorities give the average normal time 

 from commencing the nest to the completion of the set of eggs as 

 about a week. This year nesting commenced not much later than 

 usual, but the time until incubation commenced was extended 

 from a normal of one week to from two to three weeks. 



Geothlypis trichas brachidactyla. I have previously taken sets 

 of these eggs from May 28 to June 6. Chapman gives New York 

 City dates as May 25 to June 15, and Bishop, New Haven dates 

 as ]\Iay 28 to June 18. 



This year I took a set of fresh eggs June 10, and a set with in- 

 cubation just begun, June 15. 



This second nest was found finished on June 4. On June 12 

 there were four eggs, but the birds were not seen, although I watched 

 nearly an hour. On June 15, incubation had just commenced. 

 The period of deposit of eggs was in this case clearly prolonged, 

 and the dates seem later than the average. 



Icteria virens. This species breeds abimdantly, dates in former 

 years running from May 22 to June 15. I found six nests in 

 varying stages, but none of them contained eggs up to June 15. 



Seiunis aurocapillus. I have previously taken these eggs from 

 May 23 to June 6. The latest fresh eggs were May 26, and in all 

 sets subsequent to that date incubation was advanced. Chapman 

 gives New York City dates of May 20 to July 5, and Bishop, New 

 Haven, May 30 to July 10. The later dates are clearly second 

 sets. The average for the first sets would therefore appear to be 

 the last week in May. This year I found four sets, all fresh, — 

 one May 30, one June 10, and two June 12. The nest of May 30 

 was found finished on May 23. On June 12, Mr. Hoyt found a 

 nest building and took a set of fresh eggs June 22. This species 

 apparently averaged tAvo weeks later than usual. 



Seiurus motacilla. These birds are hardy, usually arriving the 

 middle of April, and nesting being well under way by May 15. 

 We naturally should not expect the cold season to affect these birds. 



The only nest I found was on May 23, containing young birds 



