3 66 



PRACTICAL ZOOLOGY 



The pelicans (Fig. 241) possess a huge membranous pouch 

 between the branches of the lower jaw, with which they scoop 

 up small fish. The common cormorant, or shag, occurs on the 

 Atlantic coast of Europe and North America and breeds on the 

 rocky shores of Labrador and Newfoundland. In China and 

 a few other countries cormorants are trained to catch fish and 

 are of considerable value to their owners. 



Ducks, Geese, and Swans. — Every one is familiar with 

 these birds, but very few have ever seen their nests, since they 



Fig. 244. — Bald eagl< 

 by Plegner.) 



Fig. 245. — Screech owl at entrance 

 to nest cavity in an oak tree. (Photo, 

 by Hegner.) 



are built principally among vegetation in marshy places where 

 people seldom disturb them. The most beautiful of all our 

 ducks is the wood duck. This bird which ranges over the 

 entire United States prefers to live near small streams, lakes, 

 and ponds. Its eggs, from six to fifteen in number, are laid in 

 cavities in the trunks or limbs of trees. The wood duck is one of 

 our game birds that is decreasing so rapidly in numbers that it 

 seems on the verge of extinction, and drastic action must be 

 taken by the federal and state governments if this species is not 

 to vanish entirely. 



Herons and Bitterns. — The herons and bitterns possess 

 long legs fitted for wading, broad wings, and short tails. 



