YELLOW WARBLER. 223 



Standing this industry, the completion of the nest, with this and 

 other small birds, is sometimes strangely protracted or not im- 

 mediately required. Yet occasionally I have found the eggs 

 of this species improvidently laid on the ground. It is amus- 

 ing to observe the sagacity of this little bird in disposing of the 

 eggs of the vagrant and parasitic Cow Troopial. The egg, de- 

 posited before the laying of the rightful tenant, too large for 

 ejectment, is ingeniously incarcerated in the bottom of the 

 nest, and a new lining placed above it, so that it is never 

 hatched to prove the dragon of the brood. Two instances of 

 this kind occurred to the observation of my friend Mr. Charles 

 Pickering; and in 1833 I obtained a nest with the adventi- 

 tious egg about two thirds buried, the upper edge only being 

 visible, so that in many instances it is probable that this spe- 

 cies escapes from the unpleasant imposition of becoming a 

 nurse to the sable orphan of the Cow Bird. She however 

 acts faithfully the part of a foster-parent when the egg is laid 

 after her own. 



I have heard of two instances in which three of the Yellow 

 Bird's own eggs were covered along with that of the Cow 

 Blackbird. In a third, after a Blackbird's egg had been thus 

 concealed, a second was laid, which was similarly treated, thus 

 finally giving rise to a three-storied nest. 



The Summer Yellow Bird, to attract attention from its nest, 

 when sitting, or when the nest contains young, sometimes 

 feigns lameness, hanging its tail and head, and fluttering feebly 

 along, in the path of the spectator ; at other times, when cer- 

 tain that the intrusion had proved harmless, the bird would 

 only go off a few feet, utter a feeble complaint, or remain 

 wholly silent, and almost instantly resume her seat. The male, 

 as in many other species of the genus, precedes a little the arri- 

 val of his mate. Towards the latter end of summer the young 

 and old feed much on juicy fruits, as mulberries, cornel berries, 

 and other kinds. 



The habitat of the present form is not extended beyond the 

 eastern base of the Rockies ; westward from that line it is replaced 

 b}' morconii, a much paler race. 



