Wild Turkey (Meleagris gallopavo) association to roads: implications for distance sampling

Abstract

Road-based distance sampling is a common technique used to estimate the density of many wildlife species but potential biases exist unless the target popula- tion is randomly distributed around roads. Our objective was to determine if and when Rio Grande wild turkeys (Meleagris gallopavo intermedia; RGWT) were randomly distributed around roads to identify time periods in which road-based surveys would be most appropriate. We used triangulated locations obtained from radiotelemetry of RGWTs in the Edwards Plateau (2001-2003), Rolling Plains (2000-2006), and South Texas (2003-2006) ecoregions. Using a geographic information system, we conducted a use and availability analysis by sex, season, and time of day for each ecoregion to determine RGWT use of areas near roads (<200 m). We found the most appropriate time to conduct road-based distance sampling was from 1 December to 15 March during morning or afternoon. Our results suggested road-based surveys conducted during these periods should yield generally unbiased results in the Rolling Plains and Edwards Plateau ecoregions. We recommend researchers and managers investigate animal distributions around roads before implementing road-based monitoring programs for other wildlife species.