PLOGCTISS: 341 
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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, ete. 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 moult 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 (7. 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-Western 
India, and North Africa; while it breeds not only in Europe, but in Southern 
Siberia, Mongolia, Turkestan, ete. 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, 
