INTRODUCTION 37 



As a result, around September 10th it is possible to see as 

 many as 80 species of birds in a day. After this date a 

 considerable body of summer residents take their final de- 

 parture and there is a general scarcity of bird-life, until the 

 first cool snap of the month brings the second group ol 

 September transients together with the first of the winter 

 visitants. The new arrivals in early September are : 



(Sept. 1-Sept, 10) 



Nashville Warbler Blackpoll Warbler 



Parula Warbler Black-throated Green Warbler 



Black-throated Blue Warbler Connecticut Warbler 



They are all occasionally recorded the last days of August. 



The second group is composed of the following species : 



(Sept. 10-Sept, 20) 



Wilson's Snipe White-throated Sparrow 



Broad-winged Hawk Palm Warbler 



Pigeon Hawk Olive-backed Thrush 



Some time between the 20th and the 30th there is usually 

 a frost attended with high northwest winds. This causes a 

 "wave" of the third group of the month's transients. Birds 

 are now as abundant individually as in May, but the number 

 of species is much less. The arrival of this group is practically 

 synchronous with the departure of many summer residents 

 and the majority of the early August transients. 



(Sept. 20-Sept, 30) 



Coot Yellow Palm Warbler 



Savannah Sparrow Brown Creeper 



Junco Golden-crowned Kinglet 



Lincoln's Sparrow Ruby-crowned Kinglet 



Myrtle Warbler Gray-cheeked Thrush 



With the commencement of October the migration be- 

 comes so irregular and so dependent upon the weather, that 

 it is almost impossible to make any general statement. One 

 might as well predict a frost or a spell of warm weather as 

 state the arrival or departure of any given species. The most 

 vital factor is, of course, a killing frost, which clears out nearly 



