Road Ecology Center

Several indirect effects of roads on wildlife communities have been reported such as habitat quality alteration, loss in landscape connectivity, and barrier effects (Forman et al., 2003; Jaeger et al., 2005). An effect zone of up to 100m on either side of the road has been described as causing measurable impacts on ecological communities (Underhill and Anglod, 2000).

Roads can impact small mammal communities by: 1) creating an edge with different habitat characteristics (Garland and Bradley, 1984; Tyser and Worley, 1992); 2) promoting the introduction of exotic species (Getz et al., 1978; Vermeulen and Opdam, 1995; Underhill and Anglod, 2000); 3) increasing stress and reducing survival (Benedict and Billeter, 2004) through disturbance and contamination (Jefferies and French, 1972; Williamson and Evans, 1972; Quarles et al., 1974); 4) blocking movement thus causing genetic barriers and home range rearrangements (Oxley et al., 1974; Garland and Bradley, 1984; Mader, 1984; Swihart and Slade, 1984; Merriam et al., 1989; Gerlach and Musolf, 2000); and finally 5) causing direct road mortality (Wilkins and Schmidly, 1980; Ashley and Robinson, 1996; Mallick et al., 1998).

While the main focus of studies on the impact of roads on small mammals has been on road barrier effects, less attention has been given to the effect of roads on density and diversity of local communities.

Further analysis on the effect of roads on natural habitats is needed. Our objective was to assess and compare density estimators and diversity of small mammal communities in areas influenced by roads with areas having no road influence.