Description: A tiny predator with long body and short legs. Total length from 7 to 13 inches. Tail 2 to 4 inches. Weight 1½ to 3⅔ ounces. This wide range in statistics is from comparing the smallest females with the largest males. Males consistently average from one-fifth to one-fourth larger than females. Summer color is dark brown with white underparts and feet. There is a white line down the insides of the hind legs connecting the white of the feet with that of the belly. The tip of the tail is black. Winter coat is all white with the exception of the black tail tip. The body is long and supple, legs are short, the neck long and round. The head is small with rather large, bulging dark eyes. The ears are large for a creature of this size. Breeding dens are usually in the ground under large rocks or among the roots under a tree. Average number of young is thought to be about four. I have a special affection for this tiny predator which, because of its fearlessness, has given me many a glimpse into its private life which would not have been possible in the case of a larger or more timid creature. Let no one underestimate the courage of this small mustelid which, if left alone, will continue its normal activities even under the close scrutiny of an observer, but if molested will often turn on its tormenter with a fury matched by few large animals. It shares these characteristics with two other relatives of the United States: the longtailed weasel (_Mustela frenata_), which is also found in the Southwest, and the least weasel (_Mustela rixosa_), which inhabits part of the northern United States, Canada, and Alaska. The short-tailed weasel will not be mistaken for either of the other species, since the least weasel has no black tip on the tail and the long-tailed weasel has a tail about one-third of its body length. The tail of the short-tailed weasel is only about one-fourth of its body length, and this species is considerably smaller than the long-tailed weasel. Short-tailed weasels are the smallest carnivores in the Southwest. In fact, except for the least weasel, they are the smallest on the North American Continent. Despite its size, _Mustela erminea_ is so hardy it ranges to the northernmost point of land in the Northern Hemisphere. This, the north coast of Greenland, is but a few degrees from the North Pole. The European form, not specifically distinct from ours, is equally hardy. It, too, inhabits not only the more temperate zones, but penetrates far north of the Arctic Circle wherever land is found. In our Southwest they are sometimes encountered at low elevations but more often in the higher mountains. Here they go through the winter change of color, but not so regularly nor so completely as in the far north.