SWANS, GEESE AND DUCKS 



(c) Tarsi, like those of the Geese, are reticulate all around, that is, 

 covered uniformly with small hexagonal scales (scutellate in Ducks); 

 hind toe with small flap or lobe; legs placed farther back than in the 

 Geese. 



(d) Windpipe of North American species (except in very young) is 

 convoluted in the keel of the sternum or breast bone (fig. 38). 



(e) As with the Geese, the annual moult consists of a single post- 

 nuptial moult during which the flight-feathers are shed simultaneously 

 and the birds become flightless for a while (Ducks have a double moult 

 or one complete and one partial moult). 



(f) Feed, like the River and Pond Ducks, by tipping and dabbling 

 in shallow places. 



GEESE 



Subfamily Anserinae 



There are, distributed throughout the 

 world, about 35 forms of Geese, of which 15, 

 including one visiting Old World species, the 

 Barnacle Goose, are regularly found in North 

 America. 



Geese form a natural connecting link be- 

 tween Swans and Ducks, the length of neck 

 and the size of body being generally interme- 

 diate between the two. 



The following features characterize this 

 Subfamily: 



(a) In most species, as in the Swans, the 

 sexes are alike in 

 colour; the body 



is raised and not so much flattened as in 

 the Ducks; the neck is longer than in the 

 Ducks, but is shorter than the body, and has 

 less than 20 vertebrae (Swans have from 22 

 to 25). 



(b) Bill is high at base, narrow in middle 

 and tapering toward end; in some species, the 

 bill appears open on the sides exposing the 

 lamellae or tooth-like serrations. The lores 

 (the space between the eye and the bill), un- 

 like those of the Swans, are completely feath- 

 ered; unlike the Ducks, they lack the cere or 

 soft swollen surface at the base of the upper 

 mandible present in some species. 



(c) Tarsi, like those of the Swans, are 

 reticulate all around, that is, covered uniform- 

 ly with small hexagonal scales (scutellate in 



FIG. 3. Typical goose 



FIG. 4. Foot and bill of 



goose, showing reticulate 



tarsus 



