U.C.U.C. DavisDavis ArboretumArboretum WildlifeWildlife ManagementManagement andand EnhancementEnhancement PlanPlan Final Report Museum of Wildlife and Fish Biology 13 January 2006 FINAL REPORT UC Davis Arboretum Wildlife Management and Enhancement Plan (AWMEP) Prepared for the UC Davis Arboretum, Facilities: Operations and Maintenance Division, and UC Davis Office of Resource Management and Planning by the UC Davis Museum of Wildlife and Fish Biology Biomonitoring Program Amanda E. Castañeda Wildlife Specialist Melanie Allen Truan, Ph.D Wildlife Ecologist 13 January 2006 Arboretum Wildlife Management & Enhancement Plan Mus. of Wildlife and Fish Biol. Occ. Papers No. 3 - 2006 Acknowledgements We wish to extend our sincere thanks to Mark McCaustland and John Kelly at Audubon Canyon Ranch who provided invaluable guidance and support with the Shields Grove heronry monitoring effort. We also wish to thank the many volunteers, interns, and Museum of Wildlife and Fish Biology staff who gave so generously of their time to collect the voluminous amount of data needed to characterize the heron colony: Ona Alminas, William Beckett, Brent Campos, Mary Chambers, Melanie Cullen, Lisa De Vellis, Robert Eddings, Cory Emerson, Sara Gillespie, Kylise Hare, Mana Hattori, Ryan Hom, Rebecca Hundt, Melissa Jackson, Teryn Kravitz, Punit Lalbhai, Erica Lindgren, Dinusha Maheepala, Danika Melcer, Ron Melcer, James Mouton, Roger Parker, Ryan Phillips, Matt Tomaso, and Irene E. Torres. We also wish to acknowledge all of those involved in the Arboretum avifaunal monitoring effort conducted over the last fifteen years by Sid England, Ronald E. Cole, and Todd Sloat. This long-term information provides a baseline against which to track population changes and the efficacy of wildlife enhancement endeavors. We would like to express our appreciation for Chris DiDio and Robert Eddings for GIS expertise in mapping and analyzing the squirrel population. Many experts assisted in the development of this Plan, including: John M. Eadie, Ronald E. Cole, Andrew Engilis, Jr., Douglas A. Kelt, Lynn S. Kimsey, Rachael F. Long, Rex E. Marsh, Peter B. Moyle, H. Bradley Shaffer, Terrell Salmon, Art M. Shapiro, Dirk H.Van Vuren, David B. Wake, Phil S. Ward, and Stanley Wright. Much information came to us by way of personal communications with experts (Appendix E). We are grateful to the Arboretum staff for providing us with information, support and resources and to Sid England, Director of the UC Davis Office of Resource Management and Planning, for his help and sage advice. This effort was supported by grants from the Institute of Museum and Library Sciences, the Glide Foundation, and the UC Davis Facilities, Operations & Maintenance Division. Contact Information: Museum of Wildlife and Fish Biology Department of Wildlife, Fish & Conservation Biology University of California, Davis 530-754-4975 [email protected] [email protected] Suggested citation: Castañeda, AE and MA Truan. 2006. UC Davis Arboretum Wildlife Management and Enhancement Plan. Mus. of Wildlife and Fish Biol. University of California, Davis, CA. Cover photos taken in UC Davis Arboretum by M. Truan (clockwise from top right): California ground squirrel (Spermophilus beechyi), western fence lizard (Sceloporus occidentalis), ruby-crowned kinglet (Regulus calendula), and immature white-crowned sparrow (Zonotrichia leucophrys). 2 Arboretum Wildlife Management & Enhancement Plan Mus. of Wildlife and Fish Biol. Occ. Papers No. 3 - 2006 Table of Contents EXECUTIVE SUMMARY ...........................................................................................................................................4 1. INTRODUCTION ....................................................................................................................................................5 2. CURRENT WILDLIFE RESOURCES ..............................................................................................................6 2.1 INVERTEBRATES ................................................................................................................................................. 7 2.2 FISH...................................................................................................................................................................... 8 2.3 AMPHIBIANS AND REPTILES ............................................................................................................................. 9 2.4 MAMMALS.......................................................................................................................................................... 10 2.4.1 Opossums ..............................................................................................................................................11 2.4.2 Bats...........................................................................................................................................................11 2.4.3 Mesocarnivores ....................................................................................................................................11 2.4.4 Ground Squirrels..................................................................................................................................12 2.4.5 Tree Squirrels........................................................................................................................................18 2.4.6 Rats ..........................................................................................................................................................18 2.4.7 Rabbits....................................................................................................................................................19 2.5 BIRDS ................................................................................................................................................................. 20 2.5.1 Temporal Patterns of Abundance ..................................................................................................23 2.5.2 Guild-based Analyses ........................................................................................................................24 2.5.3 Special Section: Shields Oak Grove Heronry .............................................................................27 3. WILDLIFE DAMAGE MANAGEMENT .........................................................................................................37 3.1 RATS AND MICE................................................................................................................................................ 37 3.2 GROUND SQUIRRELS....................................................................................................................................... 39 3.3 RABBITS ............................................................................................................................................................. 44 3.4 CATS ................................................................................................................................................................... 45 3.5 DUCKS AND GEESE.......................................................................................................................................... 46 3.6 SHIELDS GROVE HERONRY ........................................................................................................................... 49 3.6.1 Options that would not negatively affect the colony or its habitat .......................................49 3.6.2 Options with potential to negatively affect the colony, depending upon timing ..............51 3.6.3 Options with potential to reduce the size and/or density of the colony .............................51 3.6.4 Options with potential to eliminate the colony............................................................................53 3.6.5 Hazing Methods....................................................................................................................................54 4. HABITAT ENHANCEMENT.............................................................................................................................55 4.1 THE ARBORETUM WATERWAY ...................................................................................................................... 56 4.1.1 Water quality..........................................................................................................................................56 4.1.2 Waterway design..................................................................................................................................57 4.1.3 Aquatic vegetation and basking material.....................................................................................57 4.2 TERRESTRIAL HABITATS ................................................................................................................................. 58 4.2.1 Vegetation Structure and Composition ........................................................................................58 4.2.2 Water Management.............................................................................................................................58 4.2.3 Water Gardens .....................................................................................................................................59 4.3 NESTING RESOURCES ....................................................................................................................................