M080 (Mustela erminea)
STATUS: No official listed status. A furbearer; capture requires trapping license; limited
trapping season. Locally common, but rare in southern part of range.
DISTRIBUTION/HABITAT: Found at higher elevations in the middle and northern
Sierra Nevada, in pine and fir forests. Prefers mature, dense timber for breeding
and resting; meadows or other open areas for hunting.
SPECIAL HABITAT REQUIREMENTS: Ground litter, logs, stumps, or snags for den
sites; forest openings.
BREEDING: Young born in April or May; average 4 young (as many as 13 reported).
Dens located among tree roots, under rocks, in hollow logs and snags, and burrows.
TERRITORY/HOME RANGE: Home ranges varied from 25 to 37 acres (10 to 15 ha)
(Butt and Grossenheider 1976).
FOOD HABITS: Major food is voles (Microtus); also eats mice, shrews, and chip-
munks. Small but agile predator, searches for and pursues prey in logs, stumps,
dead wood, tunnels, and burrows.
OTHER: Diurnal and nocturnal; active all year. Pelage white in winter. Populations
often cyclic, patterned after prey's population cycles. Densities may reach 21/mi2
(8/km2) at high point of cycles.
REFERENCES: Hall 1951, Ingles 1965.