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Résumé :
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We conducted roadside and trail-side point count surveys to determine whether grassland bird abundance differs along ditched and non-ditched sampling points in southwestern Saskatchtewan. Savannah and Vesper Sparrows were more abundant along roads, while Baird's Sparrows, Chestnut-collared Longspurs, and Sprague's Pipits were more abundant along trails. Clay-colored Sparrows, Horned Larks, and Western Meadowlarks were detected equally along roads and trails. The lower abundance of Sprague's Pipits along roads ma) be attributed to the 20-30% reduction of suitable habitat associated with the road right-of-way within a point count of 100-m radius. Larger differences for Baird's Sparrows and Chestnut-collared Longspurs (42 and 56% less abundant along roads, respectively suggest that these species tend not to establish territories adjacent to roadside ditches. Our results indicate that roadside studies designed to estimate the abundance of grassland songbirds should either include trailside counts or interpret roadside data based on the affinity of a species for roadside habitat.
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