338 Trees, Stars, and Birds 



States. It is smaller than the crow blackbird but 

 larger than the redwing. The male is glossy greenish 

 black, the head and neck purplish black. In the female 

 the head, neck, and under parts are brownish gray. 

 These blackbirds are common both about dwellings and 

 in unsettled regions as low as the seashore and as high 

 as the timber line on Mount Shasta. They nest in 

 small colonies in sagebrush around the edges of marshes 

 or in willows or oaks. They eat cutworms, cotton-boll 

 worms, grasshoppers, weed seeds, grain, ancj fruit. 



The cowbird. The cowbird is smaller than other 

 kinds of blackbirds. The male is black except on the 

 head and neck, which are coffee-brown. The female 

 is grayish brown. Cowbirds are found throughout the 

 greater part of North America. In many of the states 

 they may be seen at all seasons. When buffaloes were 

 common on the plains, these birds were called " buffalo 

 birds," because they followed those animals about as 

 they now follow cattle. What benefit do they derive 

 from such an association ? 



Cowbirds build no nests and rear no young. The dull- 

 colored female watches her chance to lay eggs in the 

 nest of another bird when the owner is away. About 

 100 different kinds of small birds are imposed upon 

 in this way by cowbirds. These birds, when unable 

 to roll the intruder's eggs out of the nest, sometimes 

 build a second floor over the eggs and make the walls 

 higher. Nests have been found with three floors, cow- 

 birds having laid eggs on both the first and second floors. 

 As a rule the young cowbird is stronger from the first 

 than the young of the bird that built the nest, so that it 



