Volume 223, 1 May 2016, Pages 278–288
- a Centre for Wildlife Ecology, Department of Biological Sciences, Simon Fraser University, 8888 University Dr., Burnaby, British Columbia V5A 1S6, Canada
- b Wildlife Research Division, Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment Canada, Canada
- Received 1 September 2015, Revised 20 February 2016, Accepted 5 March 2016, Available online 18 March 2016
Highlights
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- Bird communities in sagebrush habitat were different when adjacent to agriculture.
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- Edge communities were characterized by generalist species and higher diversity.
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- Edge communities differed depending on adjacent crop type (orchard, vineyard).
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- Edge effects were due to local vegetation and presence of the edge.
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- Bird communities were unrelated to predators and landcover.
Abstract
Habitat
fragmentation can change the community composition of species in
remnant habitat patches. We studied the impacts of fragmentation by
agriculture on the bird community in heavily fragmented areas of the
sagebrush shrubsteppe in western North America. We examined whether bird
communities in sagebrush habitat near orchards and vineyards were
different from the community in interior sagebrush habitat, and
evaluated whether observed differences could be explained by predator
abundance, local vegetation, the presence of the habitat edge, or the
proportion of land cover in the surrounding landscape. The bird
community near agricultural edges differed from interior habitat: edge
habitats had higher species diversity and were dominated by generalist
bird species, while Vesper Sparrows, which are sagebrush-associated in
this region, were strong indicators of interior habitat. The bird
community also differed between orchard edge habitat and vineyard edge
habitat, although the difference was small. Edge effects on species
composition were associated with differences in the local vegetation,
rather than the predator community or the proportion of urban,
agricultural, and sagebrush cover on the surrounding landscape. We
suggest that differences in the bird community within edge and interior
habitat are the result of multiple mechanisms: avoidance of exotic
grasses and attraction to high shrub cover in edge habitat, attraction
to resources in adjacent habitats, and spill-over of generalist birds
from the adjacent agriculture. The results of this study suggest that
sagebrush bird conservation areas should be placed away from
agricultural development.
Keywords
- Fragmentation;
- Edge effect;
- Sagebrush;
- Agricultural edges;
- Bird;
- Predator;
- Community ecology;
- Scale;
- Landscape
Copyright © 2016 Elsevier B.V. Published by Elsevier B.V. All rights reserved.
