Ermine (Mustela erminea)

County List:

Rule:

Forested or Mixed Forested/Nonforested Landscapes

1st alternative:
      (Any Forested Upland (Regen))
      or (Any Forested Lowland (Regen))
      or Upland Brush
      or Lowland Brush
   containing:
      Dead Down Woody Debris

2nd alternative:
      (Any Forested Upland Except Conifer Plantations (Sm Saw or Lg Saw or Uneven))
      or (Any Forested Lowland (Sm Saw or Lg Saw or Uneven))
      or Treed Bog
   containing:
      Dead Down Woody Debris
   adjacent to:
      (Edge or Riparian)

Habitat List:

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Literature:

The ermine occupies a variety of habitats, including open forests, riparian woodlands, and shrubby fencerows. It is more common to the north.

Mice, voles, and shrews make up 75% of the diet, and most of the remainder comes from lagomorphs, squirrels, birds, and other vertebrates.

Habitat: Wooded or open country with thickets, rock piles, or other heavy cover; often close to water courses.

Special Habitat Requirements: Small rodents, dense brushy cover.

Habitat Preferences: The ermine is at home in a variety of arctic and boreal North American environments. Although the animal may occupy tundra (especially rocky areas) in the more southern parts of its range, open country adjacent to forest or shrub borders seems preferred. In Michigan, the ermine occurs rarely in mature forest areas and more commonly in early successional forest communities. The animal can also be found in woody cover along streams, marshes, and stone walls, in brushy fence rows, and on cleared land reverting to forest. In Gogebic and Ontonagon counties, Dice and Sherman caught individuals in black spruce and tamarack bog and in dry hardwood forest. Manville found the ermine to be the most common weasel in the Huron Mountains of Marquette County. In Delta County, the author found the species in woody cover adjacent to the shore of Lake Michigan. The ermine's habitat preference at the southern edge of its range in the Lower Peninsula is not definitely known. However, the gradual southward diminution of the northern hardwoods and boreal conifers, as the temperate hardwoods become dominant, and the lack of winter-long snow cover probably reduce the attractiveness of this environment for the ermine.

Behavior: The ermine may use either underground or above ground dens. Burrows of such prey species as voles, ground squirrels, chipmunks and other rodents are probably confiscated by the ermine. The basic shelter is a lined nest (often containing fur and feathers from prey species) with side cavities for food caches and latrines. Other den sites include hollow logs, woodpiles, stone walls, and even buildings.

Key Components of Habitat: Most abundant in ecotones within boreal, montane, and Pacific Coast forests.

Management Actions to Enhance or Maintain Habitat Quality: Maintain woodlots in agricultural areas with minimal grazing or disturbance to ensure diversity of understory vegetation and foods; maintain shelterbelts and fencerows for cover and travel corridors; encourage establishment of fruit-producing shrubs and trees.

Habitat: The short-tailed weasel inhabits a variety of habitats; arctic tundra, the northern part of the eastern deciduous forest, and the Great Plains. In North America it is most abundant in boreal, montane, and Pacific Coast coniferous forests. Soper found short-tailed weasels only in timbered areas in Canada. He found them uncommon on pine-grown sand ridges and rolling uplands but common in lower spruce-aspen parklands, streamside coniferous belts, and grassy semiwooded swamp lands. Short-tailed weasels tend to avoid dense forests, but they settle in successional or forest-edge habitats, wet meadows, marshes, ditches, riparian woodlands, or riverbanks with high densities of small mammals. Simms found that short-tailed weasels showed a preference for early successional communities such as grassland and shrubs; in contrast, long-tailed weasels showed a trend toward more advanced seral stages and were more general in their habitat preferences. He observed a 62% overlap in the habitat preferences of the two species. The local distribution of short-tailed weasels is usually related to that of small rodents and lagomorphs. Males generally occupy a wider range of habitats than females (perhaps because the distance moved by males is greater). Both males and females occupy more habitats during spring and early summer than during fall and winter.

Short-tailed weasels are well adapted to snow and live year-round at 6,560-9,840 feet in the Sierra Nevada. Normally they travel on the surface of the snow, but to catch prey they may use runways constructed under the snow by small mammals or burrow under the snow themselves.