DUCKS. 341 



metatarsus covered with scutes, and the length of that segment shorter than the 

 third toe ; while they are further characterised by having only a small membrane 

 attached to the first toe. The beak is variable ; and the number of tail-feathers 

 ranges from fourteen to eighteen. In the males, the lower end of the windpipe is 

 dilated, as it is in the spur- winged and Egyptian goose, the comb ducks, etc. None 

 of these birds are' in the habit of diving for their food. The sheldrakes resemble 

 the tree ducks in that the plumage of the two sexes is nearly alike ; but in the 

 ducks there is usually great differences between the two, the males having a very 

 beautiful coloration, with a bright metallic patch or speculum, on the wing. The 

 sheldrakes further agree with the tree ducks in having but a single annual moult; 

 whereas, in many of the ducks, the males mouit their contour-feathers once in the 

 early summer and again in autumn. The subfamily comprises a very large 

 number of species arranged under many genera, and having an almost world-wide 

 distribution, although most widely spread during the winter of the Northern 

 Hemisphere. The exigencies of space admit of a reference only to some of the 

 more important genera. In addition to the similarity in the coloration of the 

 sexes and their single moult, the sheldrakes are characterised by the presence of a 

 conspicuous white patch on the front of the wing, by the relative length of the 

 metatarsus (above which a portion of the tibia is bare), and also by the prevalence 

 of chestnut, black, and white — often in strongly contrasting masses — in the 

 plumage. The beak is about equal in length to the head, and higher than broad at 

 the base (near which are situated the nostrils), with the nail bent down and hooked. 

 In the long and powerful wings, the second quill is the longest. The sheldrakes 

 form a group of six species, breeding in the temperate regions of Europe, Asia, 

 Africa, and Australia, and visiting India and the adjacent countries in winter, but 

 quite unknown in the New World. 



Common The handsomest and, in Europe, the best known representatives 



Sheldrake, of the genus is the common sheldrake, or burrow duck (T. cornuta), 

 which is sufficiently characterised by the head and neck being dark glossy green, 

 below which is a broad collar of white, followed by a band of rich chestnut ex- 

 tending across the back and breast ; the remainder of the plumage being mainly 

 black and white, with the speculum of the wing marked by green and chestnut on 

 the secondaries. The beak is red, while the legs and toes are flesh-pink. The 

 usual length is about 25 inches. This sheldrake is essentially an inhabitant of the 

 temperate regions of the northern half of the Old World, being a resident through- 

 out the year in the British Islands, and scarcely ever penetrating within either the 

 Arctic Circle or the Tropics. From Britain its range extends to Japan, where it is 

 a winter visitor; and the limits of its migration include Persia, North-Westem 

 India, and North Africa; while it breeds not only in Europe, but in Southern 

 Siberia, Mongolia, Turkestan, etc. Essentially a coast-bird in Europe, in India the 

 sheldrake is more commonly found on inland waters, although it haunts the shores 

 of Sind. On the coasts of Europe these birds prefer sandy districts, especially 

 those with numerous rabbit-burrows, in which they breed, and hence derive their 

 name of burrow-duck. Yarrell writes that the nest is always in a burrow of some 

 sort, and frequently in one describing part of a circle, so that it may be situated as 

 much as ten or twelve feet from the entrance. It is composed of bents of grass. 



