110 J. Field Ornithol., 71(1):110–116 GRASSLAND SONGBIRD ABUNDANCE ALONG ROADS AND TRAILS IN SOUTHERN SASKATCHEWAN GLENN C. SUTTER, 1 STEPHEN K. DAVIS, AND DAVID C. DUNCAN 2 Sask Wetland Conservation Corp. 101-2022 Cornwall Street Regina, Saskatchewan, S4P 2K5 Canada Abstract.—We conducted roadside and trail-side point count surveys to determine whether grassland bird abundance differs along ditched and non-ditched sampling points in south- western Saskatchewan. Savannah and Vesper Sparrows were more abundant along roads, while Baird’s Sparrows, Chestnut-collared Longspurs, and Sprague’s Pipits were more abun- dant along trails. Clay-colored Sparrows, Horned Larks, and Western Meadowlarks were de- tected equally along roads and trails. The lower abundance of Sprague’s Pipits along roads may 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. ABUNDANCIA DE AVES CANORAS A LO LARGO DE CARRETERAS Y TRILLOS EN EL SUR DE SASKATCHEWAN Sinopsis.—Se condujeron conteos de puntos a lo largo de carreteras y trillos para determinar si habı ´a diferencia en la abundancia de aves canoras de yerbasales en localidades con zanjas y sin-sanjas en los puntos de muestreo. El trabajo se llevo ´ a cabo en el suroeste de Saskatch- ewan. Se encontro ´ que Passerculus sandwichensis y Pooecetes gramineus eran ma ´s abundantes a lo largo de carreteras, mientras que Ammodramus bairdii, Calcarius ornatus y Anthus spra- gueii, lo eran en los trillos. Por su parte Spizella pallida, Eremophila alpestris y Sturnella ne- glecta, resultaron con similar abundancia en ambos tipos de localidades. La menor abundan- cia de A. spragueii a lo largo de carreteras puede ser atribuido a la reduccio ´n entre un 20– 30% del habitat disponible, asociado con una construccio ´n en la carretera dentro del radio de 100 metros del punto de conteo. Las grandes diferencias en A. bairdii y C. ornatus (42 y 56% menos abundantes a lo largo de carreteras, respectivamente) sugieren que estas especies no tienden a establecer territorios adyacentes a carreteras. Nuestros resultados indican que los estudios a lo largo de los ma ´rgenes de carreteras disen ˜ados para estimar la abundancia de aves tı ´picas de yerbasales, deben incluir conteos a lo largo de trillos o interpretar los datos de carreteras en armonı ´a con la afinidad de la especie al habitat marginal a lo largo de las mismas. Roadside counts offer an effective and efficient means of collecting information on bird numbers across large areas at relatively low cost. The most familiar roadside survey is the annual Breeding Bird Survey (BBS), which covers much of North America and provides standardized data for population trend analysis (Sauer and Geissler 1990). By definition, road- side surveys provide no information about species abundance in off-road 1 Current address: Royal Saskatchewan Museum, 2340 Albert Street, Regina, Saskatchewan, S4P 3V7 Canada. 2 Current address: Canadian Wildlife Service, 200-4999-98th Ave., Edmonton, Alberta, T6B 2X3 Canada.