First known observations of migratory Army Cutworm Moth (Euxoa auxiliaris) in the southern Canadian Rocky Mountains

Authors

  • Erik Peterson Independent
  • Garth Mowat

DOI:

https://doi.org/10.22621/cfn.v138i2.3141

Keywords:

Army Cutworm Moth, Euxoa auxiliaris, lipid, protein, aggregation, talus slope, food resource, Grizzly Bear, Ursus arctos horribilis

Abstract

Army Cutworm Moth (Euxoa auxiliaris) migrates long distances to mountain talus slopes where they aggregate in prodigious numbers over summer. Composed of ~70% lipid and ~25% protein at the height of summer, the moths attract Grizzly Bear (Ursus arctos horribilis) to talus slopes in certain mountain ranges in the contiguous United States to forage at aggregations. We present the first known observations of migratory Army Cutworm Moths aggregating on talus slopes in the southern Canadian Rocky Mountains of British Columbia and Alberta. Because this is a potential food resource for the bears, managers may wish to evaluate suitable moth habitat.

Published

2025-03-26

Issue

Section

Notes