Short-tailed Weasels Frequent Open, Moist Forests
The first data collected on habitat use by short-tailed weasels in Canada's western mountains finds they prefer damper forests, with open canopies.
During winter, weasels occur from valley bottom to tree-line in all forest types studied in the central Selkirk, and central and southern Purcell mountains.
They also exist throughout the full range of stand ages, from recent clearcuts to forests over 300 years old.
Near Creston, weasels are more prevalent in the Interior Cedar-Hemlock's moist subzone than the dry. In the Purcells they occur more in the Engelmann Spruce-Subalpine Fir zone than the Interior Douglas-fir and Montane Spruce biogeoclimatic zones. Higher biological productivity of the wetter ecosystems probably better supports weasels.
Small openings such as roads, watercourses and avalanche chutes attract weasels. Similarly, they gravitate towards stands with less than 10 percent crown closure, often young forests. Competition with martens for prey possibly keeps short-tailed weasels out of the closed-canopy habitat that martens prefer.
Garth Mowat and Kim G. Poole. 2005. Habitat Selection by Short-tailed Weasels in Winter. Northwest Science. 79(1): 28-36.