Thinking Like a Raven: Restoring Integrity, Stability, and Beauty to Western Ecosystems

Authors

John M. Marzluff, University of Washington, SeattleFollow
Matthias-Claudio Loretto, Technical University of MunichFollow
Cameron K. Ho, University of Washington, SeattleFollow
Georgia W. Coleman, University of Washington, SeattleFollow
Marco Restani, St. Cloud State UniversityFollow

Creative Commons License

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

Abstract

Common ravens (Corvus corax; ravens) are generalist predators that pose a threat to several rare wildlife species in the western United States. Recent increases in raven populations, which are fueled by increased human subsidies—notably food, water, and nest sites—are concerning to those seeking to conserve rare species. Due to the challenges and inefficiencies of reducing or eliminating subsidies, managers increasingly rely on lethal removal of ravens. Over 125,000 ravens were killed by the U.S. Government from 1996 to 2019, and annual removals have increased 4-fold from the 1990s to mid-2010s. We contend that lethal removal of ravens, while capable of improving the reproduction of rare species, is at best a short-term and ethically untenable solution to a problem that will continue to grow until subsidies are meaningfully reduced or made inaccessible to ravens. In part because of ravens’ abilities to track natural and anthropogenic resources across unfamiliar and expansive areas, the removal of subsidies can lead to sustained shifts in raven abundance, which can have long-lasting benefits for sensitive species. In the Greater Yellowstone Ecosystem, USA, for example, we documented extensive use of human subsidies during fall/winter, daily 1-way commutes regularly in excess of 50 km by territorial birds to such subsidies, and dispersals of >700 km by nonbreeders that exploited food and roost subsidies. We call for managers to embrace new approaches to subsidy reduction including: increased involvement of conservation social scientists; increased enforcement of local, state, and federal laws; and increased deployment of a diversity of new technologies to haze and aversively condition ravens. Tackling the hard job of reducing subsidies over the expansive area exploited by ravens is right because it will increase the integrity, stability, and beauty of western ecosystems.

Recommended Citation

Marzluff, John M.; Loretto, Matthias-Claudio; Ho, Cameron K.; Coleman, Georgia W.; and Restani, Marco (2021) "Thinking Like a Raven: Restoring Integrity, Stability, and Beauty to Western Ecosystems," Human–Wildlife Interactions: Vol. 15: Iss. 3, Article 22.
DOI: https://doi.org/10.26077/2525-d6f5
Available at: https://digitalcommons.usu.edu/hwi/vol15/iss3/22