Cooperative Fish and Wildlife Research Units Program: New York
Education, Research and Technical Assistance for Managing Our Natural Resources

The distribution and abundance of carnivore species can have significant impacts on ecological communities through top-down and cascading trophic effects. Several carnivore species occur in New York, and in addition to their ecological importance, they have economic and recreational value to humans as fur-bearing species. Understanding the factors that influence their spatial distribution can help managers ensure the maintenance of sustainable populations. These factors can include environmental variables that determine the suitability of habitat for a particular species or their main prey, as well as the potential for negative interspecific interactions arising from competition and intraguild predation in areas where they occur in sympatry. Occupancy models are a useful tool to determine the occurrence of species as a function of environmental covariates across the landscape, while accounting for imperfect detection. In addition, more recently developed multispecies occupancy models can elucidate the effects of interspecific interactions on species occupancy. From 2013-2015, we collaborated with the New York State Department of Environmental Conservation (NYSDEC) to conduct a non-invasive survey across western portions of New York. Results from the fisher survey resulted in the opening of conservative trapping seasons (6 days) in new wildlife management units (WMU) previously closed to trapping, based on a minimum threshold predicted occupancy level of 0.41. We are using the same fisher detection data, along with additional data on bobcats, coyotes, and red foxes in multispecies occupancy models to explore hypotheses regarding interspecific interactions and environmental correlates in determining species occupancy. These studies demonstrate the efficiency and value of large-scale camera-trapping surveys, which can detect multiple species at once. Both single-species and multispecies occupancy models can provide managers with useful information that can be used to guide decisions on harvest, conservation of habitat, and population management.