California Department of Fish and Wildlife



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Department of Fish & Wildlife
Biogeographic Data Branch

Physical Address:
1700 9th Street, 4th Floor
Sacramento, CA 95811

Mailing Address:
1416 9th Street, Suite 1266
Sacramento, CA 95814

(916) 322-2493 • Email BDB

CNDDB Newsletters

Spotted Owl Observations Database Info

Spotted Owl Database FAQ

Using the Spotted Owl Report Generator in BIOS 5 (pdf)

For questions, comments, suggestions, or information about contributing data send an email to our account.


The California Department of Fish and Wildlife's (CDFW) Spotted Owl Observations Database was started in 1973 and tracks both subspecies of Spotted Owl that occur in California. The California Spotted Owl (Strix occidentalis occidentalis) ranges in the Sierra Nevada and south and is recognized as a CDFW Species of Special Concern. The Calfornia Spotted Owl has been petitioned to be listed under the Endangered Species Act (ESA) and on July 24, 2015, the U.S. Fish and Wildlife Service (the Service) accepted the petition and initiated the status review. The Northern Spotted Owl (Strix occidentalis caurina) ranges across California's north coast and interior and is federally listed as Threatened by the Service. On August 27, 2013, the Fish and Game Commission (FGC) voted to accept the Northern Spotted Owl as a candidate species pursuant to the California Endangered Species Act (CESA). The one-year candidacy period began after the FGC published its findings on December 27, 2013.

The Service, the California Department of Forestry and Fire Protection, and commercial timber interests have used the CDFW Spotted Owl Observations Database to help assess the potential for take of Northern Spotted Owls. The presence of a long-term observation database has allowed land managers, biologists, foresters, and researchers to better evaluate the status and distribution of owl activity centers over time and space.

CNDDB and the Spotted Owl Observations Database

Both subspecies of Spotted Owl occurring in California are tracked by the Department's California Natural Diversity Database (CNDDB) but maintained in the CDFW Spotted Owl Observations Database. The CDFW Spotted Owl Observations Database is packaged with the CNDDB and governed by the CNDDB License Agreement. The Spotted Owl Observations Database has not been integrated directly into the CNDDB because management plans for both Northern and California Spotted Owls specifically address owl activity centers, and because the CNDDB follows a slightly different mapping protocol, the Natural Heritage Methodology of Element Occurrences, it doesn't track activity centers.

The Spotted Owl Observations Database and the CNDDB are accessible together in the CNDDB & Spotted Owl Data Viewer. Additionally, the CDFW Spotted Owl Observations Database is available along with RareFind data updates through the CNDDB monthly updates webpage. For more information on obtaining access to the CNDDB/Spotted Owl Viewer contact our Information Services desk at (916) 324-3812.

Spotted Owl Observations Database Updates

In 2012, the Department's Biogeographic Data Branch (BDB) released an updated spatially-explicit version of the Spotted Owl Observations Database (BIOS layer ds704). In addition to displaying the locations of owl activity centers, the updated Spotted Owl Observations Database now includes the locations of all observations, both positive and negative. Additionally, BDB created the Spotted Owl Observations Spider Diagram layer depicting the relationship between activity center and observations (BIOS layer ds705). In December 2012, BDB revised the format of reports generated from the database, changed the way USFWS Technical Assistance letters were represented in the database, and resumed entering new data. For more information, please refer to our Spotted Owl Database FAQ page.

Metadata and explanations of the fields and codes used in the Spotted Owl Database are available with the shapefiles packaged with CNDDB/RareFind or by using the Metadata button in the tool bar of the BIOS Data Viewer.

As of 2014, the database has the ability to store observations that are not associated with an activity center. Previously, any record in the database had to be tied to an activity center. This meant that an observation had to be grouped with an existing activity center or a new activity center had to be created. In some cases, neither option may be appropriate due to the distance from a known activity center or due to a lack of data indicating resident status as described in the 2012 revision of the 2011 Northern Spotted Owl Survey Protocol. We are now allowing for stand-alone detections to avoid "invalid" activity centers and long "legs" in the Spotted Owl Observations Spider Diagram layer. These detections are notated by a "POS" or "NEG" value in the MasterOwl field for positive or negative detections, respectively.

In 2014 the Barred Owl Observations Database (ds008 in BIOS) was also reformatted and updated with new data. This database tracks barred owl, Strix hybrid, and unspecified Strix detections. It is updated on a quarterly basis and is available to view in BIOS for CNDDB subscribers or by request. As the barred owl extends further into the range of the Spotted Owl this dataset can help managers assess potential impacts to Spotted Owls in their project areas.

Additionally, the BIOS Data Viewer has been updated. Help with understanding how the BIOS Data Viewer works is available on the BIOS home page (see Getting Started in BIOS 5 (pdf) and Data Viewer Tutorials).

The Future of the Database

The 2012 and 2014 database updates are important steps forward in our effort to make high-quality information about Spotted Owls readily available to foresters, managers, consultants, and researchers throughout the state. Although the database currently contains well over 140,000 records spanning the past 40 years, it is a dynamic tool that requires regular maintenance including a near-constant input of new data and corrections to old data.

We are extremely interested in obtaining new observations. Although we are prioritizing entry of recent owl locations and observations that represent new activity centers, older information and "no response" survey results are also very valuable. In the past, the majority of observations have been voluntarily provided to CDFW by numerous individuals and organizations throughout the state. We appreciate the past and current generosity of our contributors in helping us maintain the database and we look forward to continued collaboration in the future.

To meet the needs of the database's stakeholders, CDFW has hired a full-time biologist to manage the database, maintain working relationships with contributors, and reach out to potential collaborators. Please contact our Spotted Owl Database Manager at (916) 445-5006 or send an email to our account for questions, comments, suggestions, or information about contributing data.