WEASEL (Putorius nivalis)  , the smallest European species of the group of mammals of which the polecat and stoat are well-known members (see CARNIVORA) . The weasel is an elegant little animal, with elongated slender body, back much arched, head small and flattened, ears short and rounded, neck long and flexible, limbs short, five toes on each foot, all with sharp, compressed, curved claws, tail rather short, slender, cylindrical, and pointed at the tip, and fur short and close . The upper-parts, out-side of limbs and tail, are uniform reddish, brown, the under-parts white . In cold regions the weasel turns white in winter, but less regularly and only at a lower temperature than the stoat or ermine, from which it is distinguished by its smaller size and the absence of the black tail-tip . The length of the head and body of the male is usually about 8 in., that of the tail 2; in.; the female is smaller . The weasel is generally distributed through-out Europe and Northern and Central Asia; and is represented by a closely allied animal in North America . It possesses all the active, courageous and bloodthirsty disposition of the rest of the genus, but its diminutive size prevents it attacking and destroying any but the smaller mammals and birds . Mice, rats, water-rats and moles, as well as frogs, constitute its principal food . It is generally found on or near the surface of the ground, but it can not only pursue its prey through holes and crevices of rocks and under dense tangled herbage, but follow it up the stems and branches of trees, or even into the water, swimming with perfect ease . It constructs a nest of dried leaves and herbage, placed in a hole in the ground or a bank or hollow tree, The Weasel (Putorius nivalis) . in which it brings up its litter of four to six (usually five) young ones . The mother will defend her young with the utmost desperation against any assailant, and has been known to sacrifice her own life rather than desert them .

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