Abundance and Species Richness of Shrews within Forested Habitats on Prince Edward Island

Abstract

Little is known about the small mammalian fauna of Prince Edward Island, particularly shrews. Although historical data indicate the presence of five shrew species on PEI (Sorex cinereus, S. fumeus, S. hoyi, S. palustris and Blarina brevicauda), recent studies have failed to capture S. fumeus, S. hoyi and S. palustris on the Island. During a study designed to examine the abundance of amphibians in 11 forest fragments located in the central region of Prince Edward Island, we collected 344 shrews in pitfall traps. Sorex cinereus was the most abundant species captured, and was present in all forest fragments. Blarina brevicauda was captured in all but one forest fragment. Sorex fumeus was found in only one fragment. Sorex hoyi and S. palustris were not captured during this study. No significant correlations were found between physical characteristics of forest remnants (i.e., area, perimeter, ratio area:perimeter) and the total abundance, species richness or species diversity of shrews. However, shrew captures were correlated with various biotic characteristics including ground temperature, the presence of canopy cover, number of stumps and number of logs. We conclude that both B. brevicauda and S. cinereus are common and widespread-distributed on Prince Edward Island. In conjunction with other recent studies, our findings indicate that S. hoyi is extremely rare on the Island and that it is possible that the species is extirpated from Prince Edward Island. We stress the need for a more comprehensive study specifically designed to determine the abundance, distribution and conservation status of shrew species on Prince Edward Island.