Long-tailed Weasel, Mustela frenata, movements and diggings in alfalfa fields inhabited by Northern Pocket Gophers, Thomomys talpoides

Abstract

Little is known about the movements of Long-tailed Weasels (Mustela frenata) in alfalfa (Medicago spp.) fields inhabited by Northern Pocket Gophers (Thomomys talpoides). In central Alberta, I intermittently followed the movements of Long-tailed Weasels during two consecutive winters. Three types of movements were observed: straight-line movements across the fields; sinuous movements along the edges of the field; and arc movements within the field, over concentrations of Northern Pocket Gopher burrow systems. Arc movements were 0.6-28-m-wide at their base, and extended from 6 to 45 m into the field. Movements of Long-tailed Weasels into the fields were accompanied by fresh diggings in Northern Pocket Gopher burrow systems, which became inactive thereafter. This study suggests that Long-tailed Weasels may have a cognitive map of the distribution of Northern Pocket Gophers in their home range.