BIRDS AND THEIR SEASONS 7 



Grackle and the Bed-winged Blackbird. A few Bluebirds 

 and a fairly large number of Song Sparrows winter in south- 

 ern Connecticut and in the lower Hudson Valley, but in 

 March the number becomes vastly larger, as the army from 

 the south arrives. Most of the winter birds are still here, 

 so that the March list is the winter list plus the March ar- 

 rivals. In April, a larger number of species arrive from still 

 farther south, but a few of the winter residents now leave 

 for their summer homes, so that they must be subtracted 

 from the April list. May brings back all the birds that 

 have wintered south of us, as far south in many cases as 

 Central or South America. It also drives northward our 

 winter visitants, so that these no longer appear on the list. 

 Some of these, such as the Tree Sparrow, breed outside the 

 limits of the United States, so that they need not enter into 

 our calculations again till they return in the fall ; many 

 others, such as the Brown Creeper and the Golden-crowned 

 Kinglet, though they now vanish from Connecticut, Massa- 

 chusetts, and the lower Hudson Valley, go no farther than 

 the Adirondacks, New Hampshire, Vermont, or Maine to 

 breed ; these therefore appear later in the list of the sum- 

 mer birds of those regions. Some of the March migrants, 

 too, such as the Box Sparrow, pass farther north in April 

 beyond the Canadian boundary and do not appear again in 

 our lists till the fall. Others, both of the March and April 

 arrivals, pass into northern New England and New York to 

 breed, but are eliminated from our May list in the southern 

 and central portions of our field. 



By the middle of June, all birds are on their breeding 

 grounds ; lists of birds seen in the latter half of June and 

 early July include only the permanent residents and the 

 summer residents. But inasmuch as the summer birds of 

 northern New York and New England differ so much from 

 those of the rest of the field, as is more fully explained 

 under the heading Distribution, the division of the key 



