Detecting Swift Fox: Smoked-Plate Scent Stations Versus Spotlighting

摘要

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.