90 THE WILSON BULLETIN No. 63. 



4, 1005, one was taken, and in 1907 a few were seen each day from 

 August 2G to 29, when the last evidently departed. 



168. *Dendroica pcnsylvanica. Chestnut-sided Warbler. 



Common spring migrant and regular, but in more limited num- 

 bers, in the fall. May 14, 1905, it was common, but we saw none 

 May 20-21, 190. Among the other extraordinary occurrences of tli 

 spring of 1907 was the great numbers of this species noted June 

 1. We estimated the numbers seen that day as 150. In the fall wo 

 noted a few at the beginning and end of our stay, September 4-15. 

 One each day September 3, 18 and 19, 1906, and several were noted 

 daily between August 29 and the time of our departure, September 

 6, 1907. 



1G9. *Dendroica castanea. Bay-breasted Warbler. 



A common spring and fall migrant. May 14, 1905, it was almost 

 abundant and was certainly the most common warbler migrant on the 

 Point May 20-21, 190G, was a little late for their normal migration, 

 but the abnormal spring of 1907 saw them still present in consider- 

 able numbers June 1. None were noted May 1-4, 1908. In the fall 

 we have seen them in fair numbers on all of our September trips, in 

 1907 as early as August 26. They generally come in company with 

 the Black-polls, which rather outnumber them in abundance, and 

 which they so closely resemble in fall as to make the separation of 

 the two species sometimes most difficult even to the most expert. It 

 is rare, however, though it is sometimes said to occur, that a trace 

 of the spring buff -is not to be observed on the sides of the adults or 

 a warm ochraceus suffusion is not noticeable on the sides of the ju- 

 veniles of the species. The lack of the faint streaks on the 

 breast, which usually show up on the Black-poll in life out of all 

 proportion to their intensity as observed in dry skins, is diagnostic. 

 The under-tail coverts of the Bay-breast are also cream color, while in 

 the Black-poll they are pure white. The color of the feet is said to be 

 of value in separating the two species, it being stated that, in the 

 Bay-breast these parts are dusky, while in the Black-poll they show 

 a more yellowish brown color. This may be somewhat helpful in 

 fresh birds, but in dry skins the difference, according to our series 

 of specimens, is so slight and variable as to be of little use in de- 

 termining the specific designation. 



170. *Dendroica> striata. Black-poll Warbler. 



The peculiar spring distribution of this bird in this and adjoining 

 sections of Michigan was touched upon by the authors in the Auk, 

 1907, p. 146-7. It is a very rare spring migrant at Detroit and, up 

 to 1907, no spring records had been made for the county. At Port 

 Huron, at the foot of Lake Huron, it is more common. It is abun- 



