Ecology and Management of Burrowing Owls in California

Much of the concern for burrowing owls in western North America arises from their documented and suspected changes in distribution and abundance, as well as alterations of its environment, such as reductions of burrowing mammals and intensive pesticide use. These issues were recently documented in the U. S. Fish and Wildlife Service's Status Assessment and Conservation Plan. Many of these concerns are relevant in California, where large resident (breeding) and non-resident (wintering) populations exist. To better understand burrowing owl population dynamics in different habitat types, we established four intensive study areas in California in the key habitats burrowing owls occupy.

We selected four habitats in which to locate demographic study sites: (1) the urban environment, (2) intensive agriculture areas that surround small habitat patches, (3) agriculture areas in which owls nest primarily along irrigation ditches and canals, and (4) large grasslands that reflect the best examples of the native open grassland habitat and landscape typical of burrowing owls in California. This study applies both an observational and experimental approach in answering questions that relate to factors affecting the dynamics of burrowing owl populations.

Our primary objective is to understand factors affecting survivorship and productivity. We are using recent advances in mark-recapture methods to estimate survival rates and to evaluate and rank models that include various environmental and biological factors that are potentially responsible for differences among individuals and study sites. Marking individuals also allows us to estimate movement rates of young and adults, as well as to track the productivity of individual female owls.

We are also exploring the importance of additional factors, such as individual animal characteristics, pesticide exposure, diet, and microhabitat conditions, that may affect demographic parameters. These questions are the subject of on-going graduate student projects and were recently summarized in the U.S. Fish and Wildlife Service's Status Assessment and Conservation Plan.

See the Burrowing Owl in The Imperial Valley with BBC's

The Really Wild Show

                                                                   Click on photo to see the Owl episode (Quick Time Player)

With support from

The Bureau of Land Management

and the

National Fish and Wildlfie Foundation,

we have prepared a synthesis of our research on the ecology and conservation of the Burrowing Owl in California. We are updating this report with further interpretation and managment implications. Stay tuned!

The report is large, and maybe difficult to download. Click here for a copy of the pdf.

Current Publications

Former Graduate Students:
        Jennifer Gervais, Ph.D.
           Evaluation of contaminants, demographics,  and space-use of burrowing owls in an agro-ecosystem.

        Kate Haley, M.S.
           Relationship of nest attendance and predation on the reproductive success of burrowing owls: A field

        Noelle Ronan, M.S.
           Environmental and biological factors affecting reproductive success and site fidelity of burrowing owls
           (Athene cunicularia) in a grassland ecosystem.

        Daniel Catlin, M.S. Candidate

           Within- and Between-Season Breeding Dispersal of Burrowing Owls in Grassland and Agricultural             Environments

        The Institute for Bird Populations
        Dr. Lynne Trulio, San Jose State University

Primary Sponsors:
        Bureau of Land Management, Bakersfield Field Office
        U. S. Navy, Engineering Field Activity West
        U. S. Fish and Wildlife Service
        California Department of Fish and Game
        National Wildlife Foundation
        Southern Gas

check out the Natural History videos and DVD

Burrowing Owl
Natural History and Conservation in California

Information Brochure in PDF format

Updated May 2009
An Adaptive Management Plan

For The Burrowing Owl Population
At Naval Air Station Lemoore
Lemoore, California