280 ANATID^, SWANS. 



passing notice. They are salacious to a degree remarkable even in the hot-blooded, 

 passionate class of birds ; a circumstance rendering the production of hybrids 

 frequent, and favoring the study of this subject. If we recall the peculiar actions 

 of geese nipping herbage, and of ducks "dabbling" in the water, and know that 

 some species, as the mergansers, pursue fish and other live prey under water, we 

 have the principal modes of feeding. Nidification is usually on the ground ; 

 sometimes in a hollow tree ; the nest is often warmly lined with live feathers ; 

 the eggs are usually of some plain pale color, as greenish or creamy ; the clutch 

 varies in number, commonly ranging from half a dozen to a dozen and a half. 

 The young are clothed with stiflish down, and swim at once. Among the ducks 

 and mergansers, marked sexual diversity in color is the rule ; the reverse is the 

 case with swans and geese. A noteworthy coloration of many species, especially 

 of ducks, is the speculum; a brightly colored, generally iridescent, area on the 

 secondary quills. Most of the species are migratorjr, particularly those of the 

 northern hemisphere ; the flight is performed in bands, that seem to preserve 

 discipline as well as companionship ; and with such regularity, that no birds are 

 better entitled to the claim of weather-prophets. 



There are upward of 175 species of this family, inhabiting all parts of the world. 

 They differ a good deal in minor details, and represent a number of peculiar genera 

 aside from the ordinary types, though none are so aberrant as to endanger the 

 integrity of the group. It is difficult to establish divisions higher than generic, 

 because the swans, geese and ducks, if not also the mergansers, are closely united 

 by intermediate genera. But the five groups presented as subfamilies in the 

 following pages, and representing the whole of the family, may be conveniently 

 recognized, and are readily distinguished, so far as our species are concerned, 

 by the characters assigned. 



Subfamily CYGNIN^E. Stvans. 



A strip of hare skin betiveen the eye and bill; tarsi reticulate. In the swans, the 

 neck is of extreme length and flexibility ; the movements and attitudes on the water 

 are proverbiall}^ elegant and graceful. The bill equals or exceeds the head in length ; 

 it is high and compressed at base (where sometimes tuberculate), flatter and 

 widened at the end ; the nostrils are median. Some of the inner remiges are 

 usually enlarged, and when elevated in a peculiar position of the wing, they act as 

 sails to help the course of the bird over the water. The legs are placed rather far 

 back for this family, so that the gait is awkward and constrained. The tail is short, 

 of 20 or more feathers. Although the voice is sonorous at times, an habitual 

 reticence of swans contrasts strongly with the noisy gabbling of geese and ducks ; 

 it is hardly necessary to add, that their fancied musical ability, either in health or 

 at the approach of death, is not confirmed by examination of their vocal apparatus ; 

 this is in many cases convoluted as already described, but there are no syringeal 

 muscles nor other apparatus for modulating the voice. There are eight or ten 

 species, of various countries, among them the celebrated black swan of Australia, 

 Chenopsis atratus, the black-necked swan of South America, Oygnus nigricoUis ; 

 and the Coscoroha anatoides of the same country, a species with feathered lores ; in 

 none of these docs the trachea enter the breast-bone. Our two species belong to 

 the subgenus Olor, distinguished from Oygnus proper by absence of a tubercle 

 at the base of the bill. The sexes are alike throughout the group. 



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