CORRIDOR USE AND THE ELEMENTS OF CORRIDOR QUALITY - CHIPMUNKS AND FENCEROWS IN A FARMLAND MOSAIC

An important issue in developing practical conservation actions and in understanding how corridors function is that Of identifying what constitutes a high quality corridor for a particular species or assemblage. We studied the use of fencerow corridors by the eastern chipmunk Tamias striatus to identify the elements of corridor quality for an animal species. Chipmunks were trapped in four woods and 18 fencerows of varying width, habitat and linear continuity, in farmland near Ottawa, Canada. There were many recorded movements by individuals within and between fencerows and woods. Chipmunks used fencerows in at least two main ways, and the elements of corridor quality were found to differ for these two modes of use. Resident individuals lived within and along many fencerows, thus promoting continuity of the resident population between woods. They favoured fencerows with tall trees and a woodland structure; neither fencerow width nor linear continuity accounted for additional variation in the number of residents after habitat attributes were included in a stepwise regression model. Transient chipmunks, those trapped once only in a fencerow, apparently used the fencerow network as a pathway through farmland Linear continuity of fencerows was the most important correlate of the number of transients, with habitat attributes explaining additional variance in a regression model. Fencerows with grassy vegetation alone were never used by chipmunks and, like the surrounding farmland, appear to be inhospitable habitat. The different ways that individuals may use corridors, and the differing elements of corridor quality, have implications for models of corridor use and metapopulation function, and for practical corridor management and restoration.