Fisher Potential Habitat Cores and Stepping Stones

Final set of fisher potential habitat cores and stepping stones used in fisher least cost corridor modeling. Cores are defined as polygons with predicted probability of occurrence > 0.4 (from predicted probability of fisher occurrence) and area > 2500 ha (approximately 5 female home ranges). Areas with urban or open water cover types; slopes > 80%; or high severity fires (2005-2010) were removed. Areas within 1260 m of one another were considered as part of the same core. Continuous cores were subdivided at the Merced and San Joaquin Rivers. Some polygons meeting the criteria for potential core habitat were removed based on expert opinion on their occupancy and suitability.

Stepping stones were included to show low potential fisher habitat in the gap in high potential fisher habitat between the Pit and North Fork Feather Rivers. Stepping stones are defined as polygons with predicted probability of fisher occurrence > 0.3 and area > 2500 ha.

Predicted probability of fisher occurrence layer was created by CBI from 3 sources: 

Davis, F.W., C. Seo, and W.J. Zielinksi. 2007. Regional variation in home-range-scale habitat models for fisher (Martes pennanti ) in California. Ecological Applications 17:2195-2213.

Spencer,W., H. Rustigian-Romsos, J. Strittholt, R. Scheller, W. Zielinski, and R. Truex. 2010. Using occupancy and population models to assess habitat conservation opportunities for an isolated carnivore population. Biological Conservation. In press. doi:10.1016/j.biocon.2010.10.027.

Zielinski, W., J. Dunk, S. Yaeger, and D. LaPlante. 2010. Developing and testing a landscape suitability model for fisher (Martes pennanti ) in forests of interior Northern California. In review.