Document Type


Publication Date



College of Forest Resources and Environmental Science


Wolves (Canis lupus), a once widely distributed species, were systematically removed from many temperate zone ecosystems due to conflicts with humans. A change in human attitudes and cultural norms has brought about a recovery in some suitable areas, yet reintroductions are still controversial. Two notable reintroduction areas in the United States were Yellowstone and Isle Royale National Parks. Both proposals caused polarization and debate. In Yellowstone opposition focused on outside the park effects, mainly wolves killing livestock and wild game also desired by human hunters. At Isle Royale, opposition was mostly about human interventions into nature and impairment of wilderness values contrary to the spirit of 1964 Wilderness Act. Both locations had periods in the 20th century with and without wolves and the presence of wolves had a dampening effect on ungulate population fluctuations. Most outcomes of reintroduction at Yellowstone were predicted as the Environmental Impact Statement written beforehand correctly predicted 78% of the 51 outcomes that were examined. Wolves were too recently reintroduced to Isle Royale to make similar comparisons, but we conclude that intervention is not contrary to the Wilderness Act, nor author Howard Zahniser's vision, partially because wolf reintroduction was a mitigation for human actions. Also, not intervening, or inaction, often perceived as safer, would have had more damaging impacts to ecosystem functioning.

Publisher's Statement

© 2021 The Authors. Conservation Science and Practice published by Wiley Periodicals LLC. on behalf of Society for Conservation Biology. Publisher’s version of record:

Publication Title

Conservation Science and Practice

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.


Publisher's PDF



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.