Sierra Nevada Foothills Wildlife Connectivity Modeling Project - CDFW (2015)

The northern Sierra Nevada foothills (NSNF) wildlife connectivity project modeled wildlife corridors for focal species between 271 landscape blocks within the northern Sierra Nevada foothills and neighboring ecoregions. The linkages incorporate data and information for 30 focal species, including 9 passage species (species that move through the corridor) and 21 corridor dwellers (species that may take more than one generation to move through a corridor). The linkages are made up of a least-cost corridor union and additional habitat patch information for corridor dwellers. The least-cost union is a union of the least-cost corridor analysis, based on species specific habitat models, for nine focal passage species (total number of corridors identified for each species follows the species name): black bear (47), black-tailed jackrabbit (105), bobcat (81), dusky-footed woodrat (98), gray fox (85), mountain lion (66), mule deer (134), western gray squirrel (99) and western pond turtle (84). Many species corridors were overlapping despite diverse habitat needs and the use of species specific data to build the habitat suitability models. Habitat areas for corridor dwellers, based on habitat suitability modeling and patch analysis, was added to the least-cost union: We identified all habitat patches within the corridor union, measured distance between each habitat patch to make sure it was within the maximum dispersal distance for that corridor dweller, and when needed added habitat near the corridor edge to meet the species dispersal needs. Redundant corridors were deleted to provide cleaner linkage areas. This analysis identified multiple swaths of habitat that species have the potential to reside in or move through. To ensure that ecological processes were protected in each linkage, we imposed a minimum width of 1 km for linkages. For more information see the project report at [https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=85358].