Distribution of Sorex minutus and Sorex araneus (Mammalia: Insectivora) within a forest area in Western Norway

Abstract

We collected shrews using pitfall traps in a forest area in Kvam, Hordaland, Western Norway in 1997- 98. Altogether, 205 individuals of pygmy shrew, Sorex minutus and 129 individuals of common shrew, Sorex araneus were collected. Both shrew species occurred over a wide range of forest types. Common shrew was absent in bogs and pygmy shrew apparently was absent in alder forest. Common shrew was relatively evenly distributed among forest types while the catches of pygmy shrew was significantly lower in deciduous forest than in pine forest, and this may suggest that the pygmy shrew is partially excluded from these areas by the common shrew. Catches of shrews showed no unambiguous correlation with catches of arthropods. Shrew catches were only weakly related to variation in forest productivity, humidity and tree cover. For both species the number of animals caught was highest in June and July, with rather few specimens caught in early spring and late autumn/winter.

Keywords

• habitat distribution
• interspecific competition
• pitfall traps
• shrews