256 LAND-BIRDS. 



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 bis companions, who soon perish, while he grows to 

 fill up gradually the space left.^^i 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 

 return to the neighborhood of Boston, where, at that season, 

 they are most often seen in small flocks, in which the females 

 predominate. In moving about the country, they generally 

 perch on or near the tops of trees, and from the very summit 

 of some pine their notes may often be heard. They feed upon 

 seeds, and upon insects, particularly beetles, to obtain which 

 they frequent roads, pastures, and plowed lands. From 

 their fondness of seeking food about cattle their common 

 name has arisen. When on the ground, they move with an 

 extremely awkward gait, which is ordinarily a walk, though 

 occasionally more rapid in the pursuit of some insect. The 

 male pays his court, such as it is, to several females indiffer- 

 ently; and these latter, when ready to lay, retire from the 

 flock. They become anxious, skulk about from bush to bush 

 and tree to tree, as if troubled by a guilty conscience, and 

 watch the motions of the smaller birds. On discovering a 

 nest, they seize the opportunity of absence on the part of its 

 owners to drop their eggs, and then return to their compan- 

 ions. After these ceremonies one both hears and sees less of 

 the Cow-birds than before, until the autumn, when, joined by 



1"! As he claims all the time of his foster-mother, her own eggs are often 

 suffered to decay before being hatched. 



