EFFECTS OF FOREST FRAGMENTATION BY AGRICULTURE ON AVIAN COMMUNITIES IN THE SOUTHERN BOREAL MIXEDWOODS OF WESTERN CANADA

Abstract

Abstract Little is known about the effects of forest fragmentation on bird communities in the boreal forests of western North America. Assessing the impact of forest fragmentation on bird communities has been complicated by the fact that few studies have applied statistical analyses that account for the possibility that individuals are randomly dispersed within landscapes. From 1993–1997, we contrasted bird communities in contiguous forest (54 sites) and nearby forest fragments surrounded by agricultural land (106 sites, 0.2–123 ha). Species were divided into groups based on migratory strategy (resident, short-distance migrant, long-distance migrant, and irruptive) and edge-sensitivity (edge, edge-interior, and interior). For each group, we tested whether richness and abundance were different from what would be expected if birds were distributed randomly across landscapes. Species richness was higher than expected in contiguous forest for interior species, whereas edge and short-distance migratory species...