Modeling predator habitat to enhance reintroduction planning

Abstract

Context The success of species reintroduction often depends on predation risk and spatial estimates of predator habitat. The fisher (Pekania pennanti) is a species of conservation concern and populations in the western United States have declined substantially in the last century. Reintroduction plans are underway, but the ability of the species to establish a selfsustaining population is affected by predation from its primary predator, the bobcat (Lynx rufus). Objectives To develop a habitat model that incorporates both habitat of the focal species and the spatial patterning of predator habitat. To locate areas of densely aggregated habitat that would be suitable for reintroduction. Methods Using camera survey data, we modeled the association between bobcat presence and environmental features using a classification tree. We applied this model to a spatial analysis of fisher habitat and identified reintroduction areas in the southern Washington Cascade Range. Results The classification tree predicted bobcat detection based on elevation and mean tree diameter. The final model identified fisher reintroduction locations primarily in or near existing wilderness areas. Fisher habitat areas identified considering both habitat and predation risk differed from those identified without considering predation. Conclusion Our spatial approach is unique among fisher reintroduction plans by accounting for both resource requirements and risk of predation. It can be used as a template for future reintroduction efforts in other regions and for other species. Using similar models to refine population management and reintroduction should improve the probability of successful population establishment and stability.

Citation

Halsey, Shiloh M.; Zielinski, William J.; Scheller, Robert M. 2015. Modeling predator habitat to enhance reintroduction planning. Landscape Ecology. 30(7): 1257-1271.