THE INFLUENCE OF GROVE SIZE ON BIRD SPECIES RICHNESS IN ASPEN PARKLANDS

The abundance and diversity of avifauna within 27 aspen (Populus tremuloides) groves in Saskatchewan parklands were correlated significantly with grove size. Species richness of both edge and forest dwelling species were each correlated significantly with area. Species richness of insectivores was correlated strongly with area, whereas for omnivores it was not. Migratory strategy was correlated with size of grove; species richness of permanent residents had the weakest correlation whereas long-distance migrants had the strongest. The densities of 15 bird species were correlated positively with area, densities of four species were correlated with isolation, three of those negatively and one positively, and the density of one species was correlated with both. Aspen groves as small as 1. 2 ha may be essential for some species breeding in Saskatchewan parklands.