382 GENERAL ZOOLOGY 



and driving them with loud beatings of wings into shallower 

 water, where they can be scooped up in the great pouch 

 and devoured at leisure. 



Ducks, Geese, and Swans. The group An'seres (Lat. anser, 

 " goose") is made up of water birds which have the three front 

 toes webbed and the tail comparatively well developed. The 

 ducks, geese, and swans are included here. The bill is usu- 

 ally flattened and is furnished with transverse tooth-like 

 ridges on both upper and lower mandibles. In the species 

 which frequent rivers and ponds, feeding largely on vege- 

 table food or on small mollusks, crustaceans, and larvae of 

 insects, these ridges act as a strainer through which the 

 water runs off when the bill is closed, leaving the food be- 

 hind; in the harbor species and sea-haunting, fish-eating 

 species the ridges are useful in holding the slippery food. 

 The nest is usually placed on the ground near the water. 



Wild geese have long excited interest on account of their 

 peculiar manner of migrating in a flock arranged in a long, 

 V-shaped group, keeping up the continual, sonorous "honk, 

 honk." Among the geese and swans the sexes are usually 

 alike, but in many of the ducks the male is specially orna- 

 mented with brilliantly colored plumage. Well-known spe- 

 cies of ducks are the canvasback duck, dear to the epicure ; 

 and the mallard, the ancestor of the common domestic duck. 



Herons, Storks, and Allies. The birds of the group Hero- 

 dio'nes (Gr. erodios, "heron"), often spoken of as wading 

 birds, are long-legged species, with four toes placed on about 

 the same level, and slightly or not at all webbed (Fig. 197). 

 The bill and neck are long and slender. Crests and decora- 

 tive plumes often ornament the head and neck. Herons 

 haunt the edge of ponds, lakes, and rivers, where they feed 

 on fishes and frogs, which they capture with their long, sharp 

 beaks. They nest in great colonies, usually in trees. The 

 nests are clumsy affairs made of sticks in an untidy mass. 



