Draft Recovery Plan for Four Subspecies of Island Fox (Urocyon Littoralis)
Total Page:16
File Type:pdf, Size:1020Kb
U.S. Fish & Wildlife Service Draft Recovery Plan for Four Subspecies of Island Fox (Urocyon littoralis) Island fox. Daniel Richards, used with permission. Draft Recovery Plan for Four Subspecies of Island Fox Draft Recovery Plan for Four Subspecies of Island Fox (Urocyon littoralis) (May 2012) Region 8 U.S. Fish and Wildlife Service Sacramento, California Approved: _____________________________________________________________ Regional Director, Pacific Southwest Region, Region 8 U.S. Fish and Wildlife Service Date: Draft Recovery Plan for Four Subspecies of Island Fox Draft Recovery Plan for Four Subspecies of Island Fox DISCLAIMER Recovery plans delineate reasonable actions that are believed to be required to recover and/or protect federally listed species. We, the U.S. Fish and Wildlife Service, publish recovery plans, sometimes preparing them with the assistance of recovery teams, contractors, State agencies, and others. Objectives will be attained and any necessary funds made available subject to budgetary and other constraints affecting the parties involved, as well as the need to address other priorities. Recovery plans do not necessarily represent the views nor the official positions or approval of any individuals or agencies involved in the plan formulation, other than our own. They represent our official position only after they have been signed by the Regional Director or Director as approved. Approved recovery plans are subject to modification as dictated by new findings, changes in species status, and the completion of recovery tasks. Notice of Copyrighted Material Permission to use copyrighted illustrations and images in the draft version of this recovery plan has been granted by the copyright holders. These illustrations are not placed in the public domain by their appearance herein. They cannot be copied or otherwise reproduced, except in their printed context within this document, without the written consent of the copyright holder. Literature citation should read as follows: U.S. Fish and Wildlife Service. 2012. Draft Recovery Plan for Four Subspecies of Island Fox (Urocyon littoralis). U.S. Fish and Wildlife Service, Sacramento, California. 106 pp. + appendices An electronic copy of this draft recovery plan will be made available at http://www.pacific.fws.gov/ecoservices/endangered/recovery/plans.html and http://endangered.fws.gov/recovery/index.html#plans i Draft Recovery Plan for Four Subspecies of Island Fox ACKNOWLEDGEMENTS There were many contributors to the development of this recovery plan. We would like to acknowledge the staff of the Ventura Fish and Wildlife Office, the Island Fox Recovery Coordination Group, the technical experts to the recovery team, and the researchers and field biologists for their contributions to this draft recovery plan. We appreciate the long-term commitment of the recovery team and their assistance in preparing this recovery plan over the period of development. Affiliations of the following individuals can be found in Appendix 1 of this document. Primary Authors This draft recovery plan was developed by the Island Fox Recovery Coordination Group: Brian Cypher, Carlos de la Rosa, David Graber, Devra Kleiman, Eric Morrissette, Peter Schuyler, Rebecca Shaw, Dale Steele, and Rosie Woodroffe. Peter Schuyler served as the Chair of the Recovery Team, and Eric Morrissette served as the Recovery Team Coordinator. Additional Contributors The following people provided valuable assistance in the development of this recovery plan: Vickie Bakker, Paul Collins, Tim Coonan, Dan Doak, Julie King, Colleen Lynch, Linda Munson, Kathy Ralls, Esther Rubin, Winston Vickers, Kirk Waln, and Rachel Wolstenholme. We thank the land management agencies/organizations and members of their staff for their continued support of island fox recovery efforts: the National Park Service - Channel Islands National Park, The Nature Conservancy, and the Santa Catalina Island Conservancy. We also recognize the contributions from the Integrated Island Fox Recovery Team and the Institute for Wildlife Studies in their efforts to aid in the development of this plan and promote island fox conservation and recovery. We further recognize the Friends of the Island Fox, Inc. for their efforts to promote island fox conservation and recovery through public outreach and education. ii Draft Recovery Plan for Four Subspecies of Island Fox DEDICATION This recovery plan is dedicated to the memory of Devra Kleiman and Linda Munson, who passed away in 2010. They were both instrumental in developing this plan and in constructing effective recovery actions for island foxes. Devra served on the U.S. Fish and Wildlife Service’s Island Fox Recovery Coordination Group, and as such was an author of this document. She was truly a giant in conservation biology and generously lent her considerable talents to island fox recovery. She was a passionate advocate of implementing recovery actions in a scientific manner, and of appropriate environmental education, and she successfully integrated the mainland zoo community into the island fox conservation effort. Her forthright, direct style of communication enlivened many recovery team meetings. Linda Munson was one of the world’s leading carnivore pathologists, and led studies of island fox disease and pathology since 1999. She conducted hundreds of island fox necropsies, and it is not hyperbole to say that all of our current insight into island fox health issues is due to her tireless work. Linda led the Island Fox Health Group since 1999, and under her guidance they were always the most disciplined, effective and productive of the island fox recovery team working groups. Among the issues she discovered or brought to the forefront were the unique, island-specific parasite fauna of island foxes, the nature of the canine distemper strain on Santa Catalina Island and the endemic distemper-like virus found naturally in island fox populations, chronic amyloidosis, ear tumors on Santa Catalina, and neonatal deaths from maternal neglect. iii Draft Recovery Plan for Four Subspecies of Island Fox iv Draft Recovery Plan for Four Subspecies of Island Fox EXECUTIVE SUMMARY In 2004, the U.S. Fish and Wildlife Service (FWS) listed four of the six subspecies of island fox endemic to the California Channel Islands as endangered under the Endangered Species Act of 1973, as amended (Act) following catastrophic population declines (69 FR 10335). The San Miguel Island fox (Urocyon littoralis littoralis) went from an estimated 450 individuals to 15; the Santa Rosa Island fox (U. l. santarosae) declined from over 1,750 individuals to 14; the number of Santa Cruz Island foxes (U. l. santacruzae) went from approximately 1,450 individuals to approximately 55; and the Santa Catalina Island fox (U. l. catalinae) declined from over 1,300 to 103. The San Clemente Island fox (U. l. clementae) and the San Nicolas Island fox (U. l. dickeyi) were not federally listed, as their population numbers had not experienced similar declines. However, both non-federally listed subspecies could experience the same type of population decline as those subspecies that are federally listed. Additionally, all six subspecies are listed as threatened by the State of California. Therefore, the San Clemente and San Nicolas Island fox subspecies are included for discussion in this plan where appropriate. The Channel Islands inhabited by island foxes are owned by four major landowners: the National Park Service (NPS), the U.S. Navy (Navy), The Nature Conservancy (TNC), and the Santa Catalina Island Conservancy (CIC). Although San Miguel Island is owned by the Navy, the NPS manages the island. The NPS, TNC, and CIC manage the islands where the listed subspecies occur. The FWS guides the recovery planning process for the four listed island fox subspecies under the Act. In addition, the State of California has regulatory authority over the island fox on non-Federal lands because the species is listed as threatened under the California Endangered Species Act. The two primary known threats resulting in the listing of the four subspecies of island fox as federally endangered were: 1) predation by golden eagles (Aquila chrysaetos) (San Miguel Island fox, Santa Rosa Island fox, and Santa Cruz Island fox) and 2) the transmission of canine distemper virus (Santa Catalina Island fox). Additionally, because the size of each island fox population is small, they are highly vulnerable to stochastic events and the effects of low genetic diversity. Other threats that have either contributed to the decline of island foxes or continue to affect the island fox subspecies and/or their habitat include mortality from vehicle strikes; other diseases and parasites; competition v Draft Recovery Plan for Four Subspecies of Island Fox with feral cats, deer, and pigs; habitat degradation from grazing; fire; and exposure to toxins. The current knowledge regarding the evolution, ecology, behavior, and population biology of island foxes has been amassed by numerous researchers from around the country. Collaboration with researchers has been, and will continue to be, critically important in understanding island fox natural history and recovery challenges. Recovery of each subspecies of island fox will be achieved by removing, or substantially reducing, known threats and increasing populations to viable levels for long-term survival of each subspecies. The strategy of this recovery plan is to continue the current recovery efforts and to improve and expand recovery actions as necessary.