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The distribution of avian and mammalian nest predator species in clearcut forest, forest edge and forest interior habitats was assessed on four study plots in 1992 and 1993 using line transect counts. Red squirrels (Tamiasciurus hudsonicus) and eastern chipmunks (Tamias striatus) were detected more often than expected by chance in mature forest than clearcut forest ( P < 0.05). Linear regressions of sciurid abundance incorporating conifer basal area and distance from clearcut borders explained 75% and 60% of the variation in the abundance of redsquirrels and eastern chipmunks, respectively; however, the regression equation of eastern chipmunk abundance was only marginally significant ( P = 0.07). Abundance of blue jays (Cyanocitta cristata) did not differ between clearcuts and mature forest ( P > 0.05) and was not significantly correlated with conifer basal area or distance from clearcut borders (P > 0.05). We conclude that the distribution of two important nest predator species, the eastern chipmunk and the red squirrel, are primarily influenced by the distribution of conifers. However, the distribution of eastern chipmunks and red squirrels are affected by clearcut borders as well. [ABSTRACT FROM AUTHOR]

Assessment of faunal distribution in relation to landscape features is becoming increasingly popular. Technological advances in remote sensing have encouraged regional analyses of the distributions of terrestrial vertebrates. Comparisons of the strength of association of habitat characteristics at various scales of measurement of habitat structure are rare. We compared the associations of forest cover-type, stand size-class, and stand structure to abundance of breeding bird species in managed forest in northern New England. We surveyed breeding birds and measured stand structure in 20 stands to test the hypothesis that forest cover-type, stand size-class, and structure variables were equally associated with numbers of forest birds. We fit regression models to data from each data source to predict the log number of individuals for each species. We restricted our analyses to cover-types with > 1 size-class and to size-classes representing > 1 cover-type, and restricted our comparisons to bird species with at least 10 observations/yr for 2 yr. Of 31 bird species that met our criteria for analysis. a significant ( P < 0.05) association was detected between bird abundance and structure data for 30 species, cover-type data for 19 species, and size-class data for 10 species. Stand structure was the best predictor of bird abundance for 25 species. cover-type for 5 species, and size-class for none. Of the 14 structure variables used in the analyses, total foliage volume of large and mid-size deciduoustrees, density of mid-size trees, total woody stem density, total deciduous understory volume and total volume of large conifers were most frequently important in explaining variation in species abundances.Although each species had a unique set of structural affinities, multi-layered stands are apparently more important to long-distance migrants, in general, than to resident/short distance migrants. Large-scale efforts to identify important habitats, assess degree of protection, [ABSTRACT FROM AUTHOR]