This dataset contains range maps for the Northern Elephant Seal, Mirounga angustirostris.

The northern elephant seal is the largest of the “true” seals in the Northern Hemisphere. Adult males use their large, inflatable noses during the winter breeding season to resonate sound when vocally threatening each other. The largest colonies of northern elephant seals are found off southern California in the Channel Islands. They have one of the longest migrations of any mammal; some have been recorded traveling over 13,000 miles roundtrip. Northern elephant seals were once thought to be extinct due to commercial sealing in the 1800s. A small population survived in Mexico and the population began to steadily increase in the early 1900s. Today, robust populations of northern elephant seals in the U.S. and Mexico are derived from those few hundred individuals that survived in Mexico ( NOAA 2022 ).

Vector datasets of CWHR range maps are one component of California Wildlife Habitat Relationships (CWHR), a comprehensive information system and predictive model for California's wildlife. The CWHR System was developed to support habitat conservation and management, land use planning, impact assessment, education, and research involving terrestrial vertebrates in California. CWHR contains information on life history, management status, geographic distribution, and habitat relationships for wildlife species known to occur regularly in California. Range maps represent the maximum, current geographic extent of each species within California. They were originally delineated at a scale of 1:5,000,000 by species-level experts and have gradually been revised at a scale of 1:1,000,000. For more information about CWHR, visit the CWHR webpage ( https://www.wildlife.ca.gov/Data/CWHR ). The webpage provides links to download CWHR data and user documents such as a look up table of available range maps including species code, species name, and range map revision history; a full set of CWHR GIS data; .pdf files of each range map or species life history accounts; and a User Guide.