Clapper Rail Range - CWHR B144 [ds928]

These are the same layers as appear in the CWHR System software. Citation for the CWHR System is as follows: California Department of Fish and Wildlife California Interagency Wildlife Task Group. [DATE downloaded]. CWHR version [insert version number X.X] personal computer program. Sacramento, CA.

The following information describes, and should always accompany, the California Department of Fish and Wildlife's California Wildlife Habitat Relationship System (CWHR) species distribution data. The data is organized into folders according to major taxonomic groups in CWHR. Each species is represented by a single shapefile and is named according to its 4 digit alpha-numeric CWHR ID code. The file lookup.xls contains a record for each species including its CWHR ID, scientific name, common name, and range map revision history (available for download at https://www.wildlife.ca.gov/Data/CWHR). Each layer contains the following attributes: a SHAPE_NAME or CWHR ID code, species scientific and common name, and a season code. Season codes include S for summer-only, W for winter-only, and Y for yearlong. A few species have a migration-only stopover location mapped and represented with an M. The CWHR System software contains species predictions for migration-only locations, yet most of these are not mapped. The CWHR species range maps are continually being reviewed and updated as new animal occurrence data becomes available, especially in digital format. While the original maps were digitized from 1:5,000,000 scale depictions of range, a major revision effort started in 1995 to have maps reviewed and delineated by species-level experts at a scale of 1:1,000,000. Maps dated later than 1995 are therefore much more detailed and precise in their representation of a species' range. Increasingly, species-level experts and CWHR staff have made every effort, where justified by the distribution of known species observations or known habitat associations, to represent a species' range with standard polygons of major geographic features in California such as mountain ranges, valleys, buffered river corridors, and ecological subsections of California. The smallest units of the "Ecological subregions of California: section and subsection descriptions" (Miles and Goudy, 1997. USDA Forest Service Report No. R5-EM-TP-005) capture areas with very similar soils, vegetation, precipitation, geology, climate, and geography. In cases where a population of a species is known to be isolated, its point location is buffered to a minimum radius of 2 miles. CWHR range data can be used together with vegetation maps and CWHR habitat suitability ranks to create habitat suitability maps for species using the CWHR BioVIEW program. Habitat suitability scores and the BioView program are available through the CWHR software, which is available for free download at https://www.wildlife.ca.gov/Data/CWHR. Note that habitat suitability ranks were developed based on habitat patch sizes >40 acres in size, and are best interpreted for habitat patches >200 acres in size. For further information, see the CWHR User's Guide and FAQ at https://www.wildlife.ca.gov/Data/CWHR.