OF NEW ENGLAND. 247 



the Pewees ; also, on the authority of others, the Goldfinches, 

 Meadow Larks, and Brown Thrushes. Commonly one egg, 

 sometimes two, and rarely three, or, even four, are found in the 

 chosen nest. I am satisfied, from indirect evidence, that the 

 eggs are often laid near the nest, if on the ground, and after- 

 wards placed in it. They are generally laid later than those 

 of the rightful owners, though sometimes earlier. 'The pro- 

 prietors, on discovering the intrusion, occasionally destroy the 

 foundling, still more rarely build over it a second story, or 

 even a third, which becomes the nursery for their own young, 

 or, in some cases, even desert their home ; but more often, after 

 manifestations of their displeasure, they adopt the helpless 

 stranger. As the Cow-bird's egg is almost invariably some- 

 what larger than others in the nest, it receives a larger share 

 of warmth, in consequence of which the others frequently 

 become stale, when they are removed and destroyed by the 

 parents. Even should the legitimate eggs receive an equal 

 share of warmth, those of the parasite are first hatched, since 

 they, in many cases, apparently require a shorter period of 

 incubation. Thus the young Cow-bird, who is, as I have once 

 or twice observed, hatched in the middle of the nest, is able to 

 dislodge his companions, who soon perish, while he grows to 

 fill up gradually the space left. 86 Carefully nourished and 

 brooded over until well grown, and more than old enough to 

 provide for himself, he at last leaves his foster-parents, and, 

 with a wonderful instinct, searches out and joins his own fel- 

 lows and kin. The Cow-birds lay from April until the middle 

 of June ; each female probably (from analogy) laying four or 

 five eggs in one season, and presumably at irregular intervals 

 rather than in regular succession from day to day. 



These birds are gregarious throughout the year. Before 

 November they leave Massachusetts, and migrate to the South, 

 where they often associate in large numbers with the " Red- 

 wings " or other blackbirds. About the first of April, they 



*8 AS he claims all the time of his foster-mother, her own eggs are often suffered 

 to decay before being hatched. 



