248 



BACKBONED ANIMALS. 



Island they form nests in the guano-beds, and at Fernando 

 do Norhona the nests are built on the edge of high preci- 

 pices and contain a single egg. The T. minor, at Raine 



FIG. 284. Red-headed pochard (Fultgula), showing position in 

 alighting. 



Island, northeast Australia, builds as a nest a platform of 

 twigs about eight inches in diameter, raised in the bushes. 



The American spe- 

 cies has a strong, musky 

 odor. They follow gulls 

 on the Florida reef, forc- 

 ing them to disgorge fish. 

 Their oil is sometimes 

 used in medicine. 



Order V. Ducks 

 and Geese (Lamelliros- 

 tres). Ducks (Anatida). 

 About fifty-nine spe- 

 cies of ducks (Fig. 284) 

 are known in North 

 America. They are 

 swimming birds, and have a wide geographical range, all 



FIG. 285. Swan swimming, showing 

 the web expanded and closed. 



then up. They faced the wind, which tended to blow them up and 

 away, but by pitching down slightly they seemed to ride on the gale 

 like a kite gravity acting as the string. They would retain this posi- 

 tion for hours, and it was never attempted except when the wind was 

 blowing a gale. 



