San Diego Natural History Museum--Your Nature Connection[BRCC San Diego Natural History Museum: Herpetology Department]

Birds and Mammals

Mammal Atlas
Mammal Database
Mapping Application
Distribution Modeling
Book and CDROM
  -Bat Video
  -Sample Species Account
Map Samples


Scott Tremor
fax: 619.232.0248

*If unable to open the PDF document, please download Adobe Acrobat Reader.

Mammal-Occurrence Database

The mammal-occurrence database compiles all reliable, available mammal location records into a comprehensive Geographic Information System (GIS) with numerous environmental variables. An ArcView interface and customized ArcView tools allow for flexible data input, review, queries, corrections, and analyses. Most data include a point location and a radius of the points estimated precision, because the actual observation may have been within a few meters or a few kilometers of the reported location, depending on how precise the original source was. Understanding spatial precision is critical to determining a species' habitat preferences.

Mammal Occurrence Database Map dated 08-11-2005

Data Sources

  1. Museum Collections:
    San Diego Natural History Museum, University of Arizona, Natural History Museum of Los Angeles County, Mammal Networked Information System (MaNIS), Museum of Southwestern Biology at the University of New Mexico, Museum of Vertebrate Zoology at the University of California, Berkeley, The Field Museum, Chicago, University of Kansas Natural History Museum and Biodiversity Research Center, University of Washington Burke Museum, University of Michigan Museum of Zoology, Michigan State University Museum, Texas Technical University Collections, and others.

  2. Existing GIS Databases:
    U.S. Forest Service, U.S. Fish & Wildlife Service, Anza-Borrego Desert State Park, San Diego County Bird Atlas, SANDAG regional database, California Natural Diversity Database, and others.

  3. Personal and Organization Records:
    Data obtained from numerous individuals and organizations, including Scott Tremor, San Diego Tracking Team, Drew Stokes, Wayne Spencer, San Diego County Department of Environmental Health, Kirsten Winter, U.S. Navy, Kristin Preston, Cheryl Brehme, and others.

  4. Published and Reports:
    Theses, dissertations, published literature, environmental documents, permit reports.

Database Structure

In the GIS database, each record of a species occurrence is associated with additional attribute data, such as the observer's name, the date and type of observation (e.g., trapped specimen or visual observation), a location description, and estimated spatial precision of the mapped location.

Database Status

The database has been growing steadily since we started building it in 2003.

Database Status, May 2005
San Diego County Online Mammal Atlas
Records obtained       30,000
Unique locations

We continue adding observations and assessing their accuracy and spatial precision. The database is designed to continue growing with new observations into the future.

GIS Data Layers

In addition to mammal-occurrence records, the GIS database includes a wide variety of digitally mapped environmental variables. These can be overlaid with species-occurrence points to better understand their influences on mammal distributions and habitat preferences. County-wide environmental variables include vegetation communities, soil types, elevation, climate (e.g., rainfall and temperature averaged by month), land uses, roads, and water bodies.