Detecting Swift Fox: Smoked-Plate Scent Stations Versus Spotlighting

________________________________________________ We compared two methods of detecting presence of swift fox: smoked-plate scent stations and spotlight counts. Tracks were counted on ten 1-mile (1.6-km) transects with bait/tracking plate stations every 0.1 mile (0.16 km). Vehicle spotlight counts were conducted on the same transects. Methods were compared with Spearman’s rank order correlation. Repeated measures analysis of variance was used to test the null hypothesis that there were no differences between months or between days that track and spotlight counts were conducted. We also evaluated optimum spacing of tracking plates by comparing estimates of the proportion of plates with swift fox tracks based on all plates against estimates based on a subset of plates with the latter mimicking a lower sampling intensity. Analyses of spotlight counts were limited by the preponderance of zero data points. Further, there was no defined relationship between track counts and spotlight counts. We determined that track stations could be used successfully to detect swift fox. More tracks were found in September than in July or August. We suggest a system of 1-mile (1.6-km)-long transects with four stations placed at 0.3-mile (0.5-km) intervals during late August and September. We also recommend counting tracks for 2 to 3 consecutive nights to ensure an adequate sample. habitats. This study was conducted in Fall River County, southwestern South Dakota, on private land and on lands administered by the USDA Forest Service, Buffalo Gap National Grass-land. The area, located 5 miles east of Ardmore, South Dakota, included 16 sections (4,144 ha) of mixed prairie habitat dominated by western wheatgrass ( Pascopyrum smithii ) and blue grama ( Bouteloua gracilis ). Topography was gently rolling upland straddling the divide between Mule Creek and Horsehead Creek. Small, first-order drainages flowed northwest toward Mule Creek or southeast to Horsehead Creek. Several cattle allotments were grazed in either season-long or rotation grazing systems. During the time of this study, a population of approximately 60 swift fox was being monitored in the area as part of another study. Ten 1-mile (1.6-km)-long permanent transects were es-tablished along existing roadways (pasture roads and trails). Track plates, 24 x 24 inches (61 x 61 cm), constructed of thin galvanized steel on top of 1 / 2 -inch (1.3-cm) outdoor particle board, were placed approximately 15 m off the road at 0.1-mile (0.16-km) intervals along each transect for a total of 10 plates per transect. Plates were smoked with a torch using pure acetylene (no oxygen) and a plumber’s torch tip. Smoke was applied by using a gentle back-and-forth movement with low pressure, just enough to smoke the plate without heating it. A stake hole, 1 x 1 3 ⁄ 4 inches (2.5 x 4.4 cm), was cut in the center to hold the plate in place. A small amount (about 60 g) of canned mackerel packed in oil (fig. 1) was placed near the center of each plate. Plates were placed on transects on one day and revisited every day for 3 days. Bait was freshened every day by adding either more mackerel or just