Field Mouse (Microtus pennsylvanicus)
Found anywhere in open grass-land, along hedgerows, even in suburban yards, this fat, friendly mouse is active throughout the year. In winters with good snow cover (giving predator protection) the population builds rapidly, and in spring the colony activity pattern is readily traced as the snow disappears. This mouse is not always beloved; he enjoys stripping the bark from apple, hawthorn and other trees or shrubs. While some still try to control this behavior with poisons or repellents (really poisons as well) the only real protection is a mouse-proof barrier around the tree. In early years on the Island plagues of field mice seriously threatened human food supplies; now he is just a bit of a nuisance. On the positive side, this mouse is staple food for fox, coyote, owls, several hawks, and is thus important to our environment.
Red-backed vole (Clethrionomys gapperi)
Smaller and usually less common than the field vole, this nice guy is readily identified by his reddish back and sides. This rodent is strictly a woodland-dweller, at least locally. I often see them along old stone dikes running through abandoned farmland which has reverted to forest. Also important to avian predators, this animal will thrive as long as there is reasonable cover, such as coarse debris, in the woods.