Grassland Bird Responses to Three Edge Types in a Fragmented Mixed-Grass Prairie

Avian Conservation and Ecology

Maggi S Sliwinski,¹  NicolaKoper,¹ 

[1] University of Manitoba

关键词: Chestnut-collared Longspur;    edge effects;    fragmentation;    mixed-grass prairie;    nonlinear regression;    road ecology;    Sprague;   

DOI  :  10.5751/ACE-00534-070206

学科分类：社会科学、人文和艺术（综合）

来源: Resilience Alliance Publications

【 摘 要 】

One possible factor that may have contributed to the decline of grassland bird populations is edge avoidance. In the mixed-grass prairie, habitat fragmentation is often caused by juxtaposition of habitats with vegetation that is structurally similar to prairie, making it difficult to understand why birds avoid habitat edges. We hypothesized that display height or resource-use strategy, i.e., the degree to which a species depends on grassland habitat, might explain variation in sensitivity to habitat edges among different species of grassland birds. To test our hypotheses, we used data on the abundance of grassland birds in native mixed-grass prairie fields in southern Alberta, Canada, from 2000 to 2002. Point counts were conducted up to 4.1 km from croplands, 2.2 km from roads, and 1.8 km from wetlands. We used nonlinear regression models to determine the distance at which relative abundance of 12 bird species changed in response to edge, and linear regression to determine if display height or resource-use strategy explained variation in response to different types of edges. Variation in response to edge was not explained by display height or resource-use strategy. However, six species avoided wetland edges, two avoided roads, and four avoided cropland. Two species of conservation concern, Chestnut-collared Longspurs (Calcarius ornatus) and Sprague

【 授权许可】

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