20 



THE BIRDS 



the aquatic bird. The duck has a web between its front 

 toes, and the hind toe is elevated, thus making it hard 

 for the bird to perch. It has a strongly marked bill, or flat, 

 spoon-shaped mouth. Much of the feed of the duck is 

 gotten from the mud in the bottom of streams or ponds, 

 and its mouth is especially designed for extracting feed 

 from such deep places. The gull is a common wild member 

 of this group. It is characterized by pointed wings and a 



>^. 



Fig. 9. — Royal Terna at their island nesting ground. Gulls and Terns are 

 scavengers, clearing the surface of the water and the beaches of refuse, the decay 

 of which might otherwise cause disease. (Photo by B, S. Bowdish, Secretary, 

 New Jersey Audubon Society.) 



very long tail. Geese and swans are two common domestic 

 types of this group. Geese and swans, however, live more 

 upon vegetable than animal feed. Aquatic birds differ 

 greatly in their powers of flight. The wild geese migrate 

 each year from North to South. Their powers of flight are 

 highly developed, and they are capable of remarkable speed 

 through the air. They fly in flocks, each year taking a 

 well defined and similar route. In water fowls, particularly 

 our domestic species, the nesting habit is but poorly devel- 



