Cow-bird 303 



it is generally to be seen in small flocks of six to twelve 

 individuals, in grassy meadows and corrals, in the com- 

 pany of the horses and cattle. From Beal's (1900) 

 researches it does not appear to appreciate the parasites 

 and flies found naturally about the cattle, but picks 

 up the grasshoppers and other insects disturbed by their 

 movements. The greater part of their food consists, 

 however, of seeds of noxious weeds, whose destruction 

 is a positive benefit to the farmer. 



Like the European Cuckoo, the Cow-bird builds no 

 nest and undertakes no maternal cares, but foists its 

 eggs on other birds, usually smaller than itself. Bendire 

 enumerates ninety species made use of in this way, the 

 largest being the Mourning Dove and the Meadow-Lark, 

 while the smaller Finches, Warblers and Flycatchers 

 are the commonest victims. 



It is believed that about eight eggs are laid, each in 

 the nest of a separate victim, with an interval of a day 

 or so between each ; where more than one Cow -bird's 

 egg is found in a nest, they have been laid by different 

 individuals. Sometimes they go so far as to eject the 

 eggs already in the nest, but even if this is not done 

 the eggs of the host have little chance, as the Cow-bird's 

 egg hatches in most cases more quickly, and being 

 bigger gets more warmth ; and, in the same way, if the 

 eggs of both host and parasite are hatched, the Cow-bird 

 being larger gets the lion's share of the food, so that the 

 host's nestlings are either smothered or starved. 



Bendire (95) figures an egg taken from the nest of a 

 Mountain Song-Sparrow on July 2nd, in El Paso co., 

 v/hile Aiken has taken two eggs from the nest of a Meadow- 

 Lark, near Ramah, in El Paso co., on June 4th ; Bendire 

 also states that W. G. Smith found a Cow-bird's egg 

 in a Rock- Wren's nest, under a ledge of rock fully two 



