Field immobilization and use of radio collars on long-tailed weasels

Using radiocollars to conduct relatively long-term studies of weasels (Mustela spp.) is problematic because individuals shed collars frequently and because collars may induce behavioral changes. During 1998-1999, we immobilized 16 free-ranging long-tailed weasels (Mustela frenata) using 25-mg/kg ketamine hydrochloride and 2-mg/kg xylazine hydrochloride. Mean induction time was 2 minutes and time to first arousal averaged 26 minutes. We fitted 9 male and 6 female weasels with 6.5-g and 3.2-g tuned-loop radiocollars, respectively. Of these, we observed 5 males and 2 females in captivity under semi-natural conditions. Radiocollars did not appear to influence weasel use of burrows and coarse woody debris or compromise their ability to kill prey. In the field, 8 of 9 males and all females retained collars more than one week. Males were tracked for a mean of 62 days (range=5-158 days), whereas females were tracked for a mean of 51 days (range=8-108 days). Radiocollars did not appear to adversely affect foraging or reproduction of ragged weasels.

Author T. M. Gehring and R. K. Swihart
Year 2000
Secondary title Wildlife Society Bulletin
Volume 28
Number 3
Pages 579-585