Long-tailed Weasel - Physical Description

Physical Description

The long-tailed weasel is one of the largest members of the genus Mustela in North America, with a total length of 300–350 mm and a tail comprising 40–70% of the head and body length. In most populations, females are 10–15% smaller than males, thus making them about the same size as large male stoats. The eyes are black in daylight, but glow bright emerald green when caught in a spotlight at night. The dorsal fur is brown in summer, while the underparts are whitish and tinged with yellowish or buffy brown from the chin to the inguinal region. The tail has a distinct black tip. Long-tailed weasels in Florida and the southwestern US may have facial markings of a white or yellowish colour. In northern areas in winter, the long-tailed weasel's fur becomes white, sometimes with yellow tints, but the tail retains its black tip. The long-tailed weasel moults twice annually, once in autumn (October to mid-November) and once in spring (March–April). Each moult takes about 3–4 weeks and is governed by day length and mediated by the pituitary gland. Unlike the stoat, whose soles are thickly furred all year, the long-tailed weasel's soles are naked in summer. The long-tailed weasel has well-developed anal scent glands, which produce a strong and musky odour. Unlike skunks, which spray their musk, the long-tailed weasel drags and rubs its body over surfaces in order to leave the scent,but if they are running from prey they try to hide their scent as best as possible.