Estimating resource selection and potential carrying capacity of white‐tailed deer and wild pigs to inform management strategies

Understanding spatial variability in resource selection and potential carrying capacity can improve management of wildlife species. In the southeastern United States, white‐tailed deer ( Odocoileus virginianus ; hereafter ‘deer’) are an important game species, yet deer management faces new threats from emerging diseases and invasive species such as wild pigs ( Sus scrofa ). We modelled habitat suitability for deer and wild pigs in Mississippi and subsequently estimated potential carrying capacity, which we validated using matrix population models in conjunction with current estimates of abundance and deer harvest or pig removals. Deer and wild pigs selected for greater proportions of hardwood forest and decreasing distance to water. Wild pigs also selected for, while deer avoided, increasing proportions of herbaceous and shrubby land coverages. These preferences meant that 87% and 95% of the state for deer and pigs, respectively. Depending on density, estimated carrying capacities ranged from 1.3 to 2 million deer and 370,000 to 1.2 million wild pigs. Both matrix population models for deer, assuming a maximum density of both 14.3 and 22 deer/km 2 stabilized near the state agency population estimate of 1.6 million deer; however, implied demographic rates indicated a better fit using 14.3 deer/km 2 . Population models of wild pig abundance at 27 pigs/km 2 greatly exceeded the resource‐based carrying capacity estimate, while adjustments in removals had to be conducted for the model at 8 pigs/km 2 to obtain model stability. We expect a maximum density of approximately 22 pigs/km 2 for the agency estimated carrying capacity of approximately 1 million pigs. Practical implications. Our maps indicate substantial overlap in suitable habitat for both species which could lead to habitat degradation, greater interspecific competition, or accelerated disease spread when both species are at high densities. Additionally, our work supports the idea that habitat suitability can provide a good proxy for landscape scale estimates of potential carrying capacity. While this provides a valuable baseline for management, further work to determine local scale density and vital rates will be an important next step in developing spatially explicit population models for managing deer and wild pigs.