Mesopredator predation risk limits northern bobwhite nesting habitat

Predators can significantly limit the amount of available habitat for vulnerable prey. Encouraging spatial segregation of predators and prey through habitat management prescriptions may be a useful tool to increase productivity and abundances of prey species of conservation concern. We estimated the total area of low-risk nesting habitat by interacting predator habitat selection models with northern bobwhite (Colinus virginianus) nest-site selection models. We used trail cameras, transect sampling, spotlighting transects, and incidental tracking to survey and map occurrences of mesopredators at a site in western Oklahoma, USA. We created broad-scale resource selection function models for bobwhite nest-site and mesopredator habitat selection using generalized linear models to create maps of occurrence probability in ArcGIS. Bobwhite nests were more likely to be depredated in areas of high selection by coyotes (Canis latrans) and striped skunk (Mephitis mephitis) compared to areas with low mesopredator selection. Approximately 392 ha of bobwhite nesting habitat (17%) had low probabilities of selection by both coyotes and striped skunks. Our results demonstrate the need for incorporating species’ interactions into estimations of available habitat. Based on the total area of highly selected cover by northern bobwhite, approximately 29% of the study area would have been deemed suitable for nesting. However, only 5% of that area is predicted to have low predation risk.
Methods
Species occurrence data were collected at Packsaddle Wildlife Mangement Area in western Oklahoma using a variety of survey methods: scent stations, camera traps, transects for sign, and spotlighting surveys. Cover type proportions were extracted on ArcGIS at multiple spatial scales, labeled as the radius of buffers in kilometers.