Work

Broad-scale models of a foundational alpine insect: Implications for grizzly bear ecology and conservation

Year: 2026

Type: article

Abstract: Alpine regions provide temporary habitats for many species and support complex food webs. These ecosystems are poorly described and threatened by anthropogenic stressors. The army cutworm moth (ACM) migrates great distances to aggregate in talus slopes of the Rocky Mountains during summer months. Their high energy content is attractive to grizzly bears, which ascend mountains to consume them. From 2019 to 2021, We implemented two survey techniques to elucidate grizzly bear-ACM interactions across 40 peaks in Glacier National Park, Montana. We hypothesized A) ACM occurrence would be positively associated with cool, wet, air-filled talus environments located near nectar resources, and B) grizzly bear foraging would be guided by ACM occurrence. We used field surveys of talus to create models of ACM occurrence and executed helicopter surveys of these slopes to create models of grizzly bear foraging. We determined ACM occurrence was primarily influenced by the physical characteristics of talus that provided stable, cool microclimates. These environments are rare, with ACM occurrence confined to 0.3% of Glacier. We also determined that ACM occurrence was the most influential predictor of grizzly bear foraging. Our models can help park managers develop access management strategies to limit recreational impacts on moth-foraging grizzlies. Given the importance of talus characteristics for ACM occurrence, finer-level talus characterization is needed for this foundational alpine insect, which is consumed by a variety of other species, in addition to grizzlies. Further insights into the less conspicuous species that consume this energy-rich food resource may illuminate the broader trophic significance of ACM.

Source: Biological Conservation

DOI: 10.1016/j.biocon.2026.111892

Authors: Erik Peterson, John S. Waller, Don White, Jr., James R. Pierce, Daniel H. Thornton

Institutions: University of British Columbia, Okanagan Campus, Washington State University, National Park Service, University of Arkansas at Monticello

Language: English

Topic: Wildlife Ecology and Conservation

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDG: Life on land

Open Access status: hybrid

Estimated APC paid: $3,830