Effects of edges and habitats on small mammals In a prairie ecosystem

To investigate the abundance and distribution of small mammals relative to edge in a fragmented prairie landscape, small mammals were trapped in south -central Saskatchewan from 1991 to 1993 in four different habitat types: id le pasture, delayed hay, dense nesting cover, and rights-of-way. In total, 995 small mammals, representing nine species, were captured on 14 182 trap- nights. No edge effect was recorded in idle pasture or dense nesting cover; however, an edge effect was observed in delayed hay fields. Edge effect ac ross all habitats was dependent on season: relative abundance of small mamm als was significantly higher along edges in spring but not in summer. Of th e two most common species captured, Peromyscus maniculatus showed no affini ty for edges, while Microtus pennsylvanicus was significantly more abundant along edges than in the habitat interior. Relative abundance of small mamm als was highest in dense nesting cover, intermediate in delayed hay and alo ng rights-of-way, and lowest in idle pasture. Relative abundance was also l ower in spring than in summer. Species richness was higher along edges than in the habitat interior and was also greater in summer than in spring. Spe cies diversity showed no edge or season effect.