Effects of radiotransmitters on the meadow vole, Microtus pennsylvanicus

Abstract

Investigations were carried out in both laboratory and field to determine the effect of radiotransmitters on survival, activity, and body weight in Microtus pennsylvanicus. In the laboratory, feeding rate of voles was depressed for 24 h after they were tagged with a radiotransmitter, and wheel-running activity was reduced for 72 h. Field evidence suggested that activity of transmitter-tagged voles was depressed during the first 24 h after their release, but this effect did not persist for more than 24 h after release. In winter, but not in summer and fall, weight and survival of transmitter-tagged voles were reduced compared with voles not tagged with transmitters. Voles in winter typically lost 2 to 3 g after being tagged with transmitters. Lower survival of transmitter-tagged voles in winter may have been due to greater susceptibility to predation.