A Summary of Predation by Corvids on Threatened and Endangered Species in California and Management Recommendations to Reduce Corvid Predation

A Summary of Predation by Corvids on Threatened and Endangered Species in California and Management Recommendations to Reduce Corvid Predation

State of California The Resources Agency Department of Fish and Game Habitat Conservation Planning Branch A Summary of Predation by Corvids on Threatened and Endangered Species in California and Management Recommendations to Reduce Corvid Predation by Joseph R. Liebezeit and Dr. T. Luke George Humboldt State University Department of Wildlife Arcata, California 95521 Species Conservation and Recovery Program Report, 2002-02 FINAL REPORT TO California Department of Fish and Game Species Conservation and Recovery Program 1416 Ninth Street Sacramento, California 95814 Contracts S0085015, S0085017, and S0085024 Partially Supported by Section 6 Federal Grant-in-Aid Funding for Endangered Species, California, E-2-W-15 and E-2-W-17 A Summary of Predation by Corvids on Threatened and Endangered Species in California and Management Recommendations to Reduce Corvid Predation CONTRACTOR Humboldt State University Foundation Arcata, California 95521 PRINCIPAL INVESTIGATORS AND AUTHORS Joseph R. Liebezeit and Dr. T. Luke George Humboldt State University Department of Wildlife Arcata, California 95521 2002 Citation: Liebezeit, J.R. and T.L. George. 2002. A Summary of Predation by Corvids on Threatened and Endangered Species in California and Management Recommendations to Reduce Corvid Predation. Calif. Dept. Fish and Game, Species Conservation and Recovery Program Rpt. 2002-02, Sacramento, CA. 103 pp. Front cover photographs by: Bob Burkett Common Raven and Steller’s Jay at Lake Tahoe, California A summary of predation by corvids on threatened and endangered species in California and management recommendations to reduce corvid predation Authors: Joseph R. Liebezeit Humboldt State University Department of Wildlife Arcata, CA 95521 Dr. T. Luke George Humboldt State University Department of Wildlife Arcata, CA 95521 Corvid management plan Table of Contents Table of Contents Table of Contents................................................................................................................. i List of Tables .....................................................................................................................iii List of Figures.................................................................................................................... iv ACKNOWLEDGMENTS .................................................................................................. v SUMMARY....................................................................................................................... vi INTRODUCTION .............................................................................................................. 1 CORVID LIFE HISTORIES .............................................................................................. 2 AMERICAN CROW ...................................................................................................... 2 Species description and overview ............................................................................ 2 Distribution and seasonal movement ...................................................................... 3 Habitat Use ................................................................................................................ 3 Diet ............................................................................................................................. 3 Territoriality.............................................................................................................. 4 Breeding..................................................................................................................... 4 Feeding behavior....................................................................................................... 6 Roosting behavior ..................................................................................................... 6 COMMON RAVEN ....................................................................................................... 7 Species description and overview ............................................................................ 7 Distribution and seasonal movement ...................................................................... 7 Habitat Use ................................................................................................................ 8 Diet ............................................................................................................................. 8 Territoriality.............................................................................................................. 8 Breeding..................................................................................................................... 9 Feeding behavior....................................................................................................... 9 Roosting behavior ................................................................................................... 10 STELLER’S JAY.......................................................................................................... 10 Species Description and Overview ........................................................................ 10 Distribution and Seasonal Movement ................................................................... 11 Habitat Use .............................................................................................................. 12 Diet ........................................................................................................................... 13 Feeding Behavior .................................................................................................... 13 Breeding................................................................................................................... 14 Territoriality............................................................................................................ 15 Roosting behavior ................................................................................................... 15 CORVID POPULATION TRENDS IN CALIFORNIA .................................................. 16 METHODS ................................................................................................................... 16 DOCUMENTATION OF CORVID INCREASES IN CALIFORNIA........................ 16 American Crow ....................................................................................................... 16 Common Raven....................................................................................................... 16 Steller’s Jay.............................................................................................................. 17 CAUSES OF CORVID INCREASES.......................................................................... 18 IMPORTANCE OF CORVIDS AS PREDATORS ......................................................... 31 OVERVIEW ................................................................................................................. 31 DOCUMENTATION OF THE COMMON RAVEN, AMERICAN CROW, AND ... 32 i Corvid management plan Table of Contents STELLER’S JAY AS NEST PREDATORS ................................................................ 32 DOCUMENTATION OF CORVIDS AS PREDATORS OF THREATENED........... 32 AND ENDANGERED SPECIES IN WESTERN NORTH AMERICA...................... 32 MANAGEMENT TECHNIQUES USED TO PROTECT THREATENED AND.......... 38 ENDANGERED SPECIES FROM CORVID PREDATION .......................................... 38 LETHAL REMOVAL ...................................................................................................... 38 BEHAVIORAL MODIFICATION .............................................................................. 39 Conditioned Taste Aversion................................................................................... 39 Repellents................................................................................................................. 41 Sterilants .................................................................................................................. 42 Effigies...................................................................................................................... 43 HABITAT MODIFICATION....................................................................................... 43 Nest exclosures and tortoise enclosures ................................................................ 43 Nest/perch site removal and nest destruction....................................................... 45 Habitat restoration.................................................................................................. 46 Modify anthropogenic sources of food and water................................................ 47 Providing subsidized food ...................................................................................... 47 OTHER METHODS..................................................................................................... 47 Translocation........................................................................................................... 47 Holding..................................................................................................................... 48 RESEARCH.................................................................................................................. 48 Ecology, behavior, and life histories...................................................................... 48 Monitoring..............................................................................................................

View Full Text

Details

  • File Type
    pdf
  • Upload Time
    -
  • Content Languages
    English
  • Upload User
    Anonymous/Not logged-in
  • File Pages
    113 Page
  • File Size
    -

Download

Channel Download Status
Express Download Enable

Copyright

We respect the copyrights and intellectual property rights of all users. All uploaded documents are either original works of the uploader or authorized works of the rightful owners.

  • Not to be reproduced or distributed without explicit permission.
  • Not used for commercial purposes outside of approved use cases.
  • Not used to infringe on the rights of the original creators.
  • If you believe any content infringes your copyright, please contact us immediately.

Support

For help with questions, suggestions, or problems, please contact us