Influence of cropland on resource selection by pronghorn

Abstract

Pronghorn (Antilocapra americana) are a grassland specialist that have experienced a >60% reduction in their historical range due to habitat fragmentation and encroachment of woody vegetation. Pronghorn populations are increasing in the Texas Panhandle despite conversion of grassland to cropland (27-43% of the regional landscape) and associated fragmentation. We hypothesized that pronghorn avoid cropland when selecting seasonal home ranges and avoid cropland within their home ranges. We captured 64 adult pronghorn of equal sex ratios in both the High Plains (n = 32) and Rolling Plains (n = 32) ecoregions of Texas, USA, during February 2017 and fitted them with iridium satellite global positioning system (GPS) collars. We collared 27 additional pronghorn in 2018 to account for mortalities and collar failures. We estimated resource selection functions for the High Plains and Rolling Plains populations using mixed-effects logistic regression at the home range (second order) and within home range (third order) scales separately for each ecoregion and season (fawning, summer, rut, and winter). Our hypothesis that pronghorn avoid cropland was supported in the Rolling Plains ecoregion at the home range scale; otherwise, cropland was inconsistently and seasonally important in resource selection. Furthermore, pronghorn often avoided paved roads more strongly than cropland. At the home range scale during 2017-2019, female pronghorn in the High Plains selected cropland during rut and winter. Males exhibited weak selection