The Delightful Hobby of Bird Watching [ 59 



yellow mate looks confusingly like the female orchard oriole and 

 somewhat like the female scarlet tanager; the only time it is easy 

 to identify her is when she is with her handsome husband. 



You may best appreciate the female's building prowess after 

 the family has migrated southward and you see the nest hold up 

 through wind, snow, and sleet. She works with such plant fibers 

 as the inner bark of milkweed, as well as string and other avail- 

 able materials, weaving them skillfully together. The nest, a large 

 one, is very unusual in being fastened to a branch at its rim, with 

 the bottom hanging free. Vireos are the only other birds that 

 build this type of nest, but theirs is less than two inches deep on 

 the inside much smaller than an oriole structure. 



COWBIRDS FOLLOW CATTLE 



You can find cowbirds in pastures and woodlands. Often 

 small flocks of them follow cattle. They find good hunting by 

 catching insects that infest the big animals; the birds alight on 

 the cows' backs to obtain their prey. The cowbird, smallest of our 

 native blackbirds, is undistinguished in appearance. In a good 

 light you can see that the male's head is a rich brown rather than 

 black, while the female and young have gray-brown plumage. 



Though ordinary enough in appearance, the cowbird has an 

 extraordinary and most dishonest way of providing for its young. 

 It does not build a nest! Instead, the female merely deposits an 

 egg in the home of a warbler, song sparrow, or other bird, biding 

 her time until the owner of the nest is away. 



In due course the foster mother hatches the cowbird egg with 

 her own eggs. The cowbird is invariably larger than its legitimate 

 nest-mates. It can therefore poke its head over theirs to be first 

 in line whenever the mother appears with food. The result is 

 that the intruder grows faster and often pushes the little ones 

 out of the nest to die of starvation. Occasionally a victimized bird 

 discovers the fraud in time and destroys the impostor egg, or else 

 abandons the nest to build a new one and lay a new clutch of eggs, 



The yellow warbler has an ingenious way of dealing with the 

 cowbird's maneuvering. If she discovers a strange egg, she simply 

 builds another nest over the first one. If still another cowbird 



