Long-tailed weasels, Mustela frenata, are part of the mustelidae family; badgers, martens, minks, otters, and wolverines. The long-tailed weasel is limited to the Americas; its range extends from Southern Canada to Northern South America. A close relative, the short-tailed weasel shares the American range, but can also be found in Northern Europe and Asia. The weasels living in the extreme northern areas of their range or in higher altitudes go through a moulting cycle to prepare for the winter season. Their summer coats become denser and the upperside changes from a reddish-brown to white coloring with a noticeable yellowish tint. Only the tip of the tail retains the dark color during the winter months. The moulting process begins in autumn and is triggered by the shorter daylight hours as opposed to a drop in temperature.
