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Acknowledgements
We thank Rick McIntyre and the many volunteers and visitors to Yellowstone National
Park who helped make this project possible. We are deeply appreciative to Dr. Mark
Hebblewhite and Dr. Doug Emlen for their valuable insight and feedback on this
manuscript. We additionally want to thank Brenna Cassidy and Wes Binder for their
perspective and input on the topic. This work could not be done without the safe piloting
of Mark Packila from Wildlife Air, Jim Pope from Leading Edge, Bob Hawkins from
Hawkins and Powers, Inc., Roger Stradley and Steve Ard from Gallatin Flying Service,
and Stephan Robinson and Gr ayson Sperry of Ridgeline Aviation. We would like to
thank Toni Ruth, Hornocker Wildlife Institute, and Wildlife Conservation Society for
providing cougar serum samples from northern Yellowstone during 1999–2004. We also
thank significant donors to the Yellowstone Wolf Project: Valerie Gates, Annie and Bob
Graham, and Frank and Kay Yeager. Thanks to the Cornell University Animal Health
Diagnostic Center, as well as the U. S. National Park Service, U. S. Geological Survey,
Yellowstone Forever, and the National Science Foundation (DEB- 0613730 and DEB-
1245373) for their support of this work. Any mention of trade, firm, or product names is
for descriptive purposes only and does not imply endorsement by the U.S. government.
Author contributions
C.J.M., K.A.C., and E.E.S. conceived of the research questions. E.E.B. and C.B.A. provided
conceptual advice and D.W.S. and D.R.S. provided conceptual advice and supervised the
project. D.W.S., D.R.S., E.E.S., K.A.C., C.J.M, and C.B.A. collected physical samples while
K.A.C., E.E.S., C.B.A., D.R.S., D.W.S., and E.E.B. collected observational data. K.A.C.
analyzed data and created the schematics and figures. C.J.M. and K.A.C. wrote the paper
with input from the other authors.
Competing interests
The authors declare no competing interests.
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