Biological Invasions

, Volume 17, Issue 4, pp 977–986 | Cite as

Feral cat eradication in the presence of endemic San Nicolas Island foxes

  • Chad C. Hanson
  • Wesley J. JolleyEmail author
  • Grace Smith
  • David K. Garcelon
  • Bradford S. Keitt
  • Annie E. Little
  • Karl J. Campbell
Invasion Note


Projects to eradicate invasive species from islands are a high priority for conservation. Here we describe the process used to successfully eradicate an introduced carnivore on an island where a native carnivore of similar size was also present. We primarily used padded leg-hold live trapping to capture feral cats (Felis silvestris catus). Trapped feral cats were transported off-island and housed in a permanent enclosure on the continent. We used additional methods, such as tracking dogs and spotlight hunting, to detect and remove more-difficult individuals. Project implementation caused no significant negative impacts to the endemic San Nicolas Island fox (Urocyon littoralis dickey) population. Mitigation measures included on-site veterinary resources, modified padded leg-hold live traps, conditioned trap aversion, a trap monitoring system and personnel training. To confirm eradication, we utilized camera traps and sign search data in a model to predict project success. A key part of the success of this project was the partnerships formed between NGOs, and government organizations. With support from the partnership, the use of innovative technology to improve traditional trapping methods allowed feral cats to be removed effectively in the presence of a native species occupying a similar niche. This project shows that strong partnerships, innovative methods, and use of technology can provide the conditions to eradicate invasive species when major barriers to success exist.


Ecological restoration Non-native mammals Introduced species Felis silvestris catus Trapping Urocyon littoralis dickeyi 



A special thanks to Bill Wood for assistance in refining the trapping techniques used in this project. This project was funded by the Montrose Settlements Restoration Program. Field work was conducted by IC staff: Larry Bennett, Jake Bonham, K.J.C, Nathan Fowler, Tommy Hall, C.C.H, W.J.J, Erik Oberg, Rory Stansbury, David Will, Bill Wood, and IWS staff; Hower Blair, D.K.G, Daniel Jackson, Kari Signor, Thomas Thein, Jessica Sanchez, Leslie Witter, and Winston Vickers. Greg Baxter and 2 anonymous reviewers improved an earlier draft of this manuscript. The findings and conclusions in this article are those of the authors and do not necessarily represent the view of the U.S. Fish and Wildlife Service.


  1. Aguirre-Muñoz A et al (2008) High-impact conservation action: invasive mammal eradication from the islands of western México. Ambio 37:101–107. doi:10.1579/0044-7447(2008)37[101:HCIMEF]2.0.CO;2CrossRefPubMedGoogle Scholar
  2. Algar D, Angus GJ, Brazell RI, Gilbert C, Withnell GB (2010) Eradication of feral cats on Faure Island, Western Australia. J R Soc West Aust 93:133–140Google Scholar
  3. Atkinson I (1989) Introduced animals and extinctions. In: Western D, Pearl MC (eds) Conservation for the twenty-first century. Oxford University Press, New York, pp 54–75Google Scholar
  4. Brand Phillips R, Winchell CS, Schmidt RH (2007) Dietary overlap of an alien and native carnivore on San Clemente Island. Calif J Mammal 88:173–180. doi: 10.1644/06-mamm-a-015r2.1 CrossRefGoogle Scholar
  5. Brinkerhoff JM (2002) Government-nonprofit partnership: a defining framework. Public Adm Dev 22:19–30. doi: 10.1002/pad.203 CrossRefGoogle Scholar
  6. Campbell KJ, Harper G, Hanson CC, Algar D, Keitt BS, Robinson S (2011) Review of feral cat eradications on-islands. In: Veitch CR, Clout MN, Towns DR (eds) Island invasives: eradication and management. IUCN, (International Union for Conservation of Nature), Gland, pp 37–46Google Scholar
  7. Coonan T, Ralls K, Hudgens B, Cypher B, Boser C (2013) Urocyon littoralis. The IUCN red list of threatened species. Version 2014.1. Accessed July 22, 2014
  8. Garcelon D (2009) Report on testing of methods to remove feral cats from padded leg-hold traps, San Nicolas Island, California. Institute for Wildlife Studies, ArcataGoogle Scholar
  9. Guttilla DA, Stapp P (2010) Effects of sterilization on movements of feral cats at a wildland–urban interface. J Mammal 91:482–489. doi: 10.1644/09-mamm-a-111.1 CrossRefGoogle Scholar
  10. Hanson CC, Bonham JE, Campbell KJ, Keitt BS, Little AE, Smith G (2010) The removal of feral cats from San Nicolas Island: methodology. Paper presented at the 24th vertebrate pest conference, Sacramento, CA, pp 72–78Google Scholar
  11. Island Conservation (2006) Restoring seabird populations on San Nicolas Island: testing techniques to remove feral cats. Santa Cruz, CAGoogle Scholar
  12. Island Conservation (2014a) Database of island invasive species eradications. Hosted by Island Conservation. Accessed May 16, 2014
  13. Island Conservation (2014b) Threatened island biodiversity database. Hosted by Island Conservation. Accessed May 16, 2014
  14. Jolley WJ et al (2012) Reducing the impacts of leg hold trapping on critically endangered foxes by modified traps and conditioned trap aversion on San Nicolas Island, CA, USA. Conserv Evid 9:43–49Google Scholar
  15. Medina FM et al (2011) A global review of the impacts of invasive cats on-island endangered vertebrates. Glob Change Biol 17:3503–3510. doi: 10.1111/j.1365-2486.2011.02464.x CrossRefGoogle Scholar
  16. Montrose Trustee Council (2005) MSRP restoration plan and programmatic EIS/EIR. Report of the Montrose Natural Resources Trustee Council, National Oceanic and Atmospheric Administration, U.S. Fish and Wildlife Service, National Park Service, California Department of Fish and Game, California Department of Parks and Recreation, and California State Land CommissionGoogle Scholar
  17. Nogales M et al (2004) A review of feral cat eradication on-islands. Conserv Biol 18:310–319. doi: 10.1111/j.1523-1739.2004.00442.x CrossRefGoogle Scholar
  18. Ramsey DSL, Parkes JP, Will D, Hanson CC, Campbell KJ (2011) Quantifying the success of feral cat eradication, San Nicolas Island, California. N Z J Ecol 35:163–173Google Scholar
  19. Trauger DL, Tilt WC, Hatcher CB (1995) Partnerships: innovative strategies for wildlife conservation. Wildl Soc Bull 23:114–119Google Scholar
  20. US Navy (2005) Integrated natural resources management plan San Nicolas Island, CA, 2006–2010Google Scholar
  21. U.S. Fish & Wildlife Service (2009) Final environmental assessment for the restoration of San Nicolas Island’s seabirds and protection of other native fauna by eradicating feral cats. Report on behalf of the Montrose Settlements Trustee Council and U.S. NavyGoogle Scholar
  22. Will D, Campbell K, Holmes N (in review) Using digital data collection tools to improve overall cost-efficiency and provide timely analysis for decision making during invasive species eradication campaigns. Wildl ResGoogle Scholar
  23. Will D, Hanson CC, Campbell KJ (2010) A trap monitoring system to enhance efficiency of feral cat eradication and minimize adverse effects on non-target endemic species on San Nicolas Island. Paper presented at the 24th vertebrate pest conference, Sacramento, CA, pp 79–85Google Scholar
  24. Wood B et al (2002) Removing cats from islands in northwest Mexico. In: Veitch CR, Clout MN (eds) Turning the tide: the eradication of invasive species. IUCN SSC Invasive Species Specialist Group, IUCN, Switzerland, pp 374–380Google Scholar

Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • Chad C. Hanson
    • 1
  • Wesley J. Jolley
    • 1
    Email author
  • Grace Smith
    • 2
  • David K. Garcelon
    • 3
  • Bradford S. Keitt
    • 1
  • Annie E. Little
    • 4
  • Karl J. Campbell
    • 1
    • 5
  1. 1.Island ConservationSanta CruzUSA
  2. 2.NAWCWD Sustainability OfficePoint MuguUSA
  3. 3.Institute for Wildlife StudiesArcataUSA
  4. 4.U.S. Fish and Wildlife Service1901 Spinnaker DriveVenturaUSA
  5. 5.School of Geography, Planning and Environmental ManagementThe University of QueenslandSt LuciaAustralia

Personalised recommendations