172 The Goose-like Birds 



THE SWANS, GEESE, DUCKS, AND MERGANSERS 



' (Suborder Anseres, Family Anatida) 



The members of this large assemblage are, with possibly slight exception, so 

 typically " Duck-like "in appearance that there can usually be no difficulty in their 

 recognition. They are all aquatic or semi-aquatic in their habits, and, with a 

 single exception, the Pied Goose of Australia, all have webbed feet. With 

 limited exceptions, such as the Steamer Duck of South America and a few others, 

 all the members of the group are good, not to say strong, flyers. The bill is gener- 

 ally broad and flattened, with the edges laminated, although in several groups it 

 becomes narrower and more or less tapering to a point ; in all, however, the upper 

 mandible terminates in a nail. The legs are short and usually placed far back 

 on the body, an adaptation which permits rapid movement through the water. 

 The plumage is close and compact, and there are relatively few bare spaces. It 

 is perhaps unnecessary to go into the anatomical characters, at least beyond those 

 set forth on the preceding pages, as certain of the more important details of struc- 

 ture will be taken up under the various groups. It may be stated, however, that 

 when the moult takes place the feathers of the wing are generally shed at once, thus 

 incapacitating them for flight for a short period. 



The Anseres number about seventy living genera and two hundred and ten 

 species, and are cosmopolitan in distribution, though most abundant in the 

 more northern portions of the Western Hemisphere. Several genera and a large 

 number of fossil forms have been described, yet none of them is of very great 

 antiquity. The members of this group are all more or less sociable, and may 

 often be seen feeding in flocks, and during the breeding season often nest in 

 proximity, though not in such colonies as characterize, for example, the group 

 last considered. Most of them are strongly migratory and while on these 

 journeys to and from the summer home often fly in single file or V-shaped 

 formation, under the direction of an apparently competent and trusted leader. 

 The nests are usually placed on the ground, occasionally in hollow trees, and 

 the complement of eggs is usually large, ranging from some four or five to a 

 dozen or more. These have hard, generally smooth shells and are even or 

 uniform in coloration. 



Swans. The first forms we shall consider are the Swans (Subfamily 

 Cygnin<z), which may be characterized by the very long neck, this being as 

 long as or even longer than the body. The number of vertebrae entering into 

 the neck are from twenty-three to twenty-five, whereas in the remainder of the 

 Anseres ..the number is less than twenty. They are large, markedly aquatic 

 birds and their compact bodies and gracefully curved necks make them models 

 of grace and beauty on the water. They number about eight species, disposed 

 in two genera, though upon this latter point authorities differ. The true Swans 

 may be referred for convenience to the genus Cygnus, notwithstanding the 

 fact that it is sometimes divided into two or more. With two exceptions the 

 plumage is pure white throughout, although the head is often stained with 



