Overview
Version 10 online web app is now available
The California Wildlife Habitat Relationship (CWHR) System contains life history, geographic range, and management information for more than 700 species of amphibians, reptiles, birds, and mammals that regularly occur within the state. A number of subspecies and distinct population segments (DPSs) have also been added and more information at these taxonomic and management levels will be added as it becomes available. CWHR also contains detailed information on 59 habitat types and their spatial distributions. The core of the CWHR system is a database which relates these species to each of the habitats which support them, and an intuitive user interface enabling users to query this information. CWHR products aid in understanding, conserving, and managing California's wildlife.
Previously downloaded versions of CWHR (versions 9.x and preceding) will continue to function on Windows 10, but will no longer be supported and will be drawing from static information that has not been updated since 2019. We highly recommend discontinuing use of CWHR v.9 or below, and transitioning to the online CWHR v.10. For certain uses that require the most recent data, CWHR v.9 or below may not be accepted.
We also invite you to provide feedback on the new CWHR web application. This feedback is vital to our understanding of how we can make CWHR best suited to the needs of its users.
CWHR Products
- CWHR Model (Version 10): A community-level model of 59 habitats and structural classes - rating the suitability of each habitat and class for reproduction, cover, and feeding for more than 700 vertebrate taxa. CWHR habitat classifications have become a standard for regulatory, conservation, and research issues concerning California's wildlife. The online application can be used to query for species lists by location, habitat type, and more (see types of reports below).
- CWHR Range Maps: Geographic range data by season for over 700 taxa. Range maps are available in pdf format, for online viewing in BIOS, and for download as ArcGIS shapefiles. GIS data are available below under GIS data
downloads, or through the BIOS viewer.
- CWHR Predicted Habitat Models: Raster files showing the distribution of predicted suitable habitat within each species range. Predicted habitat distribution GIS data are available for download through the BIOS viewer or by
request
.
- Guide to Wildlife Habitats of California: A habitat classification scheme for California containing
59 habitats, structural stages for most habitats, and 124 special habitat
elements.
- Complete Species List: (PDF) Catalogues over 1000 terrestrial
vertebrates that regularly occur in California.
- CWHR Life History Accounts: Life history descriptions including information on abundance, seasonality, specific habitat requirements, activity patterns, seasonal movements and migrations, home range, reproduction, niche, notes and comments, and references.
CWHR v.10 can be used to produce the following types of reports:
- Information on One or More Species: Taxonomy, legal status, life history, seasonality, locational occurrence, and CWHR model habitat suitability and element suitability ratings for selected species.
- A List of Species for a Single Condition: All wildlife species in the CWHR database predicted to occur in a user-specified habitat situation (habitat type, seral stages, location, habitat elements). More than one habitat type and stage can be specified. The query can be further limited by wildlife species legal status, seasonality, and suitability threshold levels. A typical application of the Single Situation Reports is to predict a list of species that potentially occur in a project area.
- Predicted Species Comparing Two Conditions: The report is a side-by-side comparison of predicted species for two different Single Condition queries. The Two Condition Comparison Report is useful for evaluating species lists between two different habitat scenarios for impact assessments, biodiversity considerations, or habitat management planning.
- Habitat Values for Predicted Species Comparing Two Conditions: This report compares the habitat suitability ratings for each species under differing habitat conditions. The report shows the average habitat suitability value for each species for each Single Condition query, and calculates the difference in habitat suitability value for each species. This type of Two Condition Comparison Report is useful when comparing habitat values between two different habitat scenarios for impact assessments, biodiversity considerations, or habitat management planning.
- Weighted Habitat Values for Predicted Species Comparing Two Conditions: This report is the same as the Habitat Value Comparison except that habitat types can be weighted by the user. The weights are typically based on acreage of the habitats. This type of Two Condition Comparison Report is useful when specific information to define weights, such as habitat area, is known for the two habitat conditions. This can be used to inform impact assessments, biodiversity considerations, or habitat management planning.
- A List of Species that Use a Given Element: All species that use a selected habitat element (e.g. acorns, large snags, vernal pools) to meet their requirements for breeding, feeding or cover and the degree to which each species finds that element essential.
- Life History Notes for a Single Species: General information on species life history, bibliographic references and species range maps.
- Description of a Single Habitat: General information describing composition and location of a selected habitat.
- Species List: All amphibians, birds, mammals, and reptiles known to regularly occur in California, as well as occasional occupants (vagrants) denoted with an asterisk.
User Manual
The CWHR v.10 model is now available online through your favorite browser. The CWHR User Manual (PDF) was written for version 9, the former 'download-and-install' version of CWHR. While the user interface of CWHR v.10 differs from previous versions, the basic functionality has changed very little. Therefore, much of the content of the older user manual will continue to be a valuable resource until an updated manual is complete. The online CWHR v.10 includes many navigation and usage ‘hints’ built into each screen, effectively bringing a good deal of user manual content into the application. For this reason, we are confident that users transitioning to CWHR v.10 in advance of a fully updated companion manual, will experience a relatively smooth transition to the new interface. CDFW staff who develop and maintain CWHR are available to answer any of your questions. They can be reached at CWHR@wildlife.ca.gov.
GIS Data Downloads and Supporting Materials
CWHR GIS Data:
Species Ranges (2014), (Predicted Habitat Distributions coming soon), and ranges for CWHR Habitat Types
GIS datasets were captured at 1:1,000,000 scale showing statewide range by season for the 700+ terrestrial vertebrates in CWHR and geographic ranges for the 59 CWHR habitat types.
Product Support
Conservation Applications
CWHR has been used for several large wildlife resource conservation efforts including the
California Wildlife Action Plan, the
Areas of Conservation Emphasis (ACE) project,
Safe Passages (PDF) - a habitat linkage prioritization assessment for the Central Valley Riverbank area, the
Sierra Nevada foothills wildlife connectivity modeling project, and most recently, it has supported several tools developed in support of
California's 30x30 project to conserve 30% of the states land and coastal waters by the year 2030. It is one of the primary biological data sets used in an assessment of California's biodiversity for the "
Atlas of the Biodiversity of California". CWHR is used in sustained yield planning efforts by several large private timber companies and is part of regulations adopted by the California Board of Forestry.
Field Forms and Guidelines
Research and Development
The information in CWHR is based on current published and unpublished biological information and professional judgment by recognized experts on California's wildlife. Research to improve the CWHR System is ongoing. Some examples are presented below.