Northern Prairie Wildlife Research Center
We tested a new method for determining the distribution of swift foxes in Kansas. From a sampling frame of 24 counties in western Kansas, we selected a systematic sample of alternate townships in a checkerboard pattern. During September and October 1997, experienced observers delineated suitable swift fox habitat within each sample township and searched it for evidence of occupancy (tracks, dens, and the animals themselves) by swift fox and other furbearers. Each township was searched for a minimum of 30 minutes, with searches continuing either until swift foxes were detected or for 120 minutes. Of 278 townships we selected for surveys, 242 (87.1%) were searched effectively. Adverse weather conditions prevented surveys in the three northernmost counties of our sample frame. Swift foxes were detected in 45.0% of townships surveyed, including 16 counties. Swift foxes were not detected in Morton, Seward, Stevens, and Meade counties, where the species is thought to be uncommon or absent, nor in Haskell County, although an incidental observation by one of our trackers confirmed the presence of swift fox there. Factors that interfered with track identification were the principal impediments to our survey. Tracks were difficult to discern in areas with hard or sandy soils and were sometimes obliterated by adverse weather, vehicle traffic, and agricultural activities. Conducting surveys during periods of favorable weather, in the morning, and prior to the harvest of agricultural crops might have increased detection rates. To determine how frequently we failed to detect swift fox that were present, we plan to repeat searches in 1998 in townships where swift foxes were not detected in 1997. Nevertheless, preliminary results suggest our method is a practical means for conducting landscape-scale presence/absence surveys of swift fox. Restricting searches to habitats judged best for swift foxes and most favorable for track detection helped control costs and achieve high detection rates.