Monitoring Wolverines in Northeast Oregon January 2011 – December 2012 Final Report Authors: Audrey J. Magoun Patrick Valkenburg Clinton D. Long Judy K. Long Submitted to: The Wolverine Foundation, Inc. February 2013 Cite as: A. J. Magoun, P. Valkenburg, C. D. Long, and J. K. Long. 2013. Monitoring wolverines in northeast Oregon. January 2011 – December 2012. Final Report. The Wolverine Foundation, Inc., Kuna, Idaho. [http://wolverinefoundation.org/] Copies of this report are available from: The Wolverine Foundation, Inc. [http://wolverinefoundation.org/] Oregon Department of Fish and Wildlife [http://www.dfw.state.or.us/conservationstrategy/publications.asp] Oregon Wildlife Heritage Foundation [http://www.owhf.org/] U. S. Forest Service [http://www.fs.usda.gov/land/wallowa-whitman/landmanagement] Major Funding and Logistical Support The Wolverine Foundation, Inc. Oregon Department of Fish and Wildlife Oregon Wildlife Heritage Foundation U. S. Forest Service U. S. Fish and Wildlife Service Wolverine Discovery Center Norcross Wildlife Foundation Seattle Foundation Wildlife Conservation Society National Park Service 2 Special thanks to everyone who provided contributions, assistance, and observations of wolverines in the Wallowa-Whitman National Forest and other areas in Oregon. We appreciate all the help and interest of the staffs of the Oregon Department of Fish and Wildlife, Oregon Wildlife Heritage Foundation, U. S. Forest Service, U. S. Fish and Wildlife Service, Wildlife Conservation Society, and the National Park Service. We also thank the following individuals for their assistance with the field work: Jim Akenson, Holly Akenson, Malin Aronsson, Norma Biggar, Ken Bronec, Steve Bronson, Roblyn Brown, Vic Coggins, Alex Coutant, Cliff Crego, Leonard Erickson, Bjorn Hansen, Mike Hansen, Hans Hayden, Tim Hiller, Janet Hohmann, Pat Matthews, David McCullough, Glenn McDonald, Jamie McFadden, Kendrick Moholt, Mark Penninger, Jens Persson, Lynne Price, Brian Ratliff, Jamie Ratliff, John Stephenson, John Wyanens, Rebecca Watters, Russ Westlake, and Jeff Yanke. James Short generously provided a snowmachine trailer for field work. Daarla Klages was indispensable in keeping everything running smoothly. Keith Aubry and Cathy Raley generously provided snow cover maps and unpublished data and reports. Finally, thanks to Dale Pedersen and Rod Brobeck who were our most enthusiastic cheerleaders and never doubted we would find wolverines in Oregon. Photo by Jens Persson 3 TABLE OF CONTENTS INTRODUCTION .......................................................................................................................................................5 STUDY AREA .............................................................................................................................................................6 METHODS...................................................................................................................................................................8 Integrated Motion-detection Cameras and Hair Snags.............................................................................................8 Winter....................................................................................................................................................................8 Summer..................................................................................................................................................................9 Snow Tracking from the Air.......................................................................................................................................9 RESULTS...................................................................................................................................................................10 Winter 2010-2011....................................................................................................................................................10 Camera Deployment ............................................................................................................................................10 Wolverines Detected at Camera Stations.............................................................................................................10 DNA Analysis of Hair .........................................................................................................................................12 Snow Tracking from the Ground.........................................................................................................................13 Snow Tracking from the Air................................................................................................................................13 Winter 2011-2012....................................................................................................................................................13 Camera Deployment ............................................................................................................................................13 Wolverines Detected at Camera Stations.............................................................................................................14 Snow Tracking from the Ground.........................................................................................................................16 Snow Tracking from the Air................................................................................................................................16 Summer 2012...........................................................................................................................................................17 Camera Deployment ............................................................................................................................................17 Wolverines Detected at Summer Camera Stations ..............................................................................................17 Other Species Photographed at Camera Stations ...................................................................................................17 DISCUSSION AND CONCLUSIONS.....................................................................................................................20 Deployment of Camera Stations ..............................................................................................................................20 Winter..................................................................................................................................................................20 Summer................................................................................................................................................................21 Wolverine Detections at Camera Stations...............................................................................................................21 Understanding Reasons for the Low Density of Wolverines in the Study Area .......................................................23 Habitat Quality ....................................................................................................................................................23 Size and Connectivity with Adjacent Wolverine Populations .............................................................................24 Time Needed for Population Recovery................................................................................................................26 LONG-TERM MONITORING OF WOLVERINES IN NORTHEAST OREGON...........................................28 LITERATURE CITED .............................................................................................................................................29 TABLES .....................................................................................................................................................................33 FIGURES ...................................................................................................................................................................51 Appendix A.................................................................................................................................................................76 4 INTRODUCTION Wolverine range in the contiguous United States had contracted substantially by the mid 1900s, probably because of high levels of human-caused mortality and very low immigration rates (Aubry et al. 2007). The species is currently listed as Threatened in Oregon by the Oregon Department of Fish and Wildlife. The Oregon Conservation Strategy lists the wolverine as a species for which status is unknown but habitat may be suitable to support the species in the Blue Mountains, East Cascades, and West Cascades Ecoregions of Oregon (Oregon Department of Fish and Wildlife 2006; pages 367−368). At the federal level, the U.S. Fish and Wildlife Service has recently proposed to list the wolverine as a threatened species in the contiguous U.S. under the federal Endangered Species Act (http://federalregister.gov/a/2013-01478). In their historical review of wolverine distribution in the western states, Aubry et al. (2007) concluded that wolverines detected in Oregon in recent decades “probably represent extreme dispersal events that were not representative of self-sustaining populations” because “there is no evidence of wolverine occurrence in eastern Washington or Oregon currently.” These authors used