Morphologic Variation in the Masked Shrew (Sorex cinereus) and the Smoky Shrew (S. fumeus)

-Morphologic variation in cranial characters of the masked shrew (Sorex cinereus) and the smoky shrew (S.fumeus) was assessed using multivariate statistical analyses. Matrices of correlations of characters were computed, and the first three principal components extracted. Three-dimensional projections of localities onto principal components indicated that larger male and female S. cinereus occurred in the northeastern portions of its range, along the coast of the Pacific Northwest in the United States, and in central Canada. In general, smaller body size was characteristic of animals occurring in southern latitudes. Selected environmental variables showed significant relationships with size and shape components of morphologic variation. Larger individuals of S. fumeus generally were found in the northern and central part of the distribution (West Virginia, Maryland, northern Virginia, and southern Pennsylvania). Smallest individuals occurred N of this central region and in the most southern localities. Body size of S. fumeus was correlated with selected environmental variables and interspecific relationships.