Grizzly Bears and Humans at Alpine Moth Sites in Wyoming, USA

Authors

• Erika A. Nunlist, Montana State University-Bozeman
• Dan Tyers, U.S. Forest Service
• Andrew Pils, U.S. Forest Service
• Bok F. Sowell, Montana State University-BozemanFollow

Date of this Version

Spring 2023

Document Type

Article

Citation

Human–Wildlife Interactions (Spring 2023) 17(1): article 9 

doi: 10.26077/6570-aebd

Comments

United States government work. Public domain

Abstract

Army cutworm moths (Euxoa auxiliaris; moths) are an important seasonal higher elevational food source for grizzly bears (Ursus arctos horribilis; bears) in the Greater Yellowstone Ecosystem (Wyoming, Montana, and Idaho, USA). Increased human interaction with bears at moth sites is an important management issue because of the potential for displacing bears and the concern for human safety. Managers will need better information regarding human–bear interactions at high-density moth sites that are also accessible to humans to mitigate potential conflicts. In the summers of 2017 and 2018, we studied human–bear interactions at 2 of the most human accessible moth sites in the Shoshone National Forest, Wyoming. We completed 293 bear surveys and documented 266 bear observations. We also recorded human-use levels at the 2 study sites (north site: 3 groups/year; south site: 35 groups/year). We documented 43 interactions (at the south site only) and obtained location data for 29 interactions. During human–bear interactions, bears strongly avoided humans 80% of the time and had no apparent reaction 20% of the time. Our results indicated that human safety and bear displacement are valid management concerns at the south site. Human safety concerns were most apparent in mountain climbing groups with small group sizes (people, n = 64/70) that were unprepared for encounters with bears. Management concerns for human safety and bear displacement are much lower at the north site. We recommend placing information kiosks at trailheads to inform hikers of dangers associated with grizzly bear concentrations on moth sites.