Short-tailed weasel (Ermine)
Scientific Name: Mustela erminea
The short-tailed weasel (also know as ermine or stoat) are smaller than its relative the long-tailed weasel, and namely, have a shorter tail. They have the typical weasel form: long body, short legs, long neck supporting a triangular head, slightly protruding round ears, bright black eyes, and long whiskers. They resemble a ferret! The tail length is about 35% of the total body length, ranging from 42 mm to 120 mm.
Their short, moderately fine fur is white in the winter and the tip of the tail is black. In the summer, the dorsal fur is a reddish to chocolate brown while the ventral fur extending to the upper lip is yellowish white to blend into the background of tree trunks and branches.
Don’t be fooled by these cute little guys, they are quite voracious predators!
Adult size: 6 to 12 in
Weight: Males: 67-116 grams Females: 25-80 grams
Life span: Up to 7 years in the wild
Maturity: 2 years
Litter size: 3-18
Fun Fact
Ermines may be tiny, but they are fierce! They can take down prey much larger than themselves, like a snowshoe hare!
Diet
Ermine are small fierce predators that primarily hunt at night. They prey on small mammals, rabbit-sized or smaller. When small mammals are scarce, they will switch to eating birds, eggs, frogs, fish, and insects. Ermine will cache food to keep up with their demanding metabolism.
Habitat
Ermine inhabit mostly riparian woodlands, marshes, and shrubby woodlands.
Behavior
Male and female ermine only associate with each other during the breeding season. Females do not often go far from their birthplace, while males disperse over large territories. Females are smaller and more agile than males, and hunt in underground tunnels more frequently.
Reproduction and Life Cycle
Both male and female ermine mate opportunistically, usually in the late spring to early summer. Females only produce one litter per year, born in the early spring. Gestation lasts an average of 280 days, including an 8-to-9-month period of developmental delay. When the days start to get longer in the spring, it triggers development to resume.
Population Status
Ermine are listed as of “least concern” though hunting pressure in some areas can impact their populations.
Viewing
Ermine are spread throughout New York State, though are more frequently seen in the Adirondack Park.
Range
Ermine have a circumpolar distribution and are found throughout North America and Eurasia.