CLASS AVES 



415 



Fig. 303. — The barn-owl, Aluco pratinocola (Bonaparte). The owls are noted for their 

 noiseless flight which enables them to approach their prey without being detected. This 

 one showing a defensive attitude when "cornered." {Photographed, copyrighted, and 

 contributed by Gayle Pickwell.) 



Fig. 304. — A ptarmigan, Lagopus sp., in its winter plumage which renders it incon- 

 spicuous on snow. In the summer its feathers have a mixture of brownish white and a 

 small amount of black. The feet and legs are feathered, which not only protects them 

 against the low temperatures but may aid them in traveling on the surface of soft snow, 

 {Photographed from a specimen in the University of Nebraska State Museum.) 



