Ecological research is critical for informing management of at-risk species, for example by identifying what drives occupancy of species across landscapes. However, restricting research to public land and omitting private land, as commonly occurs in ecological research, can bias inferences because important drivers of population and community patterns may vary with land ownership. We conducted a landscape-scale study of a species of conservation concern, white-tailed prairie dog (WTPD; Cynomys leucurus), across multiple land ownerships in Wyoming. We quantified how WTPD occupancy varied with both land ownership and biotic and abiotic factors. We established a baseline occupancy rate for WTPD in Wyoming, and quantified how this baseline would have been biased if we had restricted our study to public land.
Results/Conclusions
We surveyed 440 sites throughout the Wyoming range of WTPD, which included sites on public (275), private (80), checkerboard (55), and Wind River Indian Reservation (30) land. We found that WTPD were four-times as likely to occupy private as public land at the median elevation. WTPD occupancy increased with bare ground, but also when recent plant biomass (as estimated by NDVI) was higher than a site’s long-term average biomass. In other words, WTPD tended to occupy sparsely vegetated sites, but occupancy increased with short-term increases in biomass. The strong land ownership effect illustrates how study area delineation in relation to land ownership can influence, and potentially misinform, research inferences and management actions, and why it is counterproductive for conservation to presuppose that certain land ownerships contain poor quality habitat. Ecologically, the variation in occupancy resulting from long-term site conditions relative to short-term conditions, such as changes in plant biomass, can be used to improve WTPD population monitoring.