Wildlife habitat associations in eastern hemlock - birds, smaller mammals, and forest carnivores

Abstract

Ninety-six bird and forty-seven mammal species are associated with the hemlock type in the northeastern United States. Of these species eight bird and ten mammal species are strongly associated with the hemlock type though none of these species are limited to it. Hemlock species richness appears to be lower than in other conifer or hardwood types. Avian habitat considerations include the distribution and variety of structural habitat features throughout managed and unmanaged stands in sustainable patterns. Sawtimber hemlock stands support significantly higher bird communities than young stands. Smaller mammal habitat considerations include dense patches of coniferous regeneration, hard mast-producing inclusions, cavity trees, coarse woody debris, and wetland seeps and inclusions. Forest carnivore habitat considerations include the availability and distribution of predictable prey and suitable cover opportunities (cavity trees, coarse woody debris, wetland seeps and inclusions, and rocky ledge and well-drained den sites). Differences of ten or more inches of annual precipitation distinguish most northern New England landscapes from the majority of landscapes in the western Great Lakes region. Northern New England landscape level habitat elements include lower slope positions and imperfectly drained, excessively drained, or shallow to bedrock sites.