Jannett, F.J. Jr. 1983. Population stability and structure of the rock vole, Microtus chrotorrhinus, in northeastern Minnesota. Report submitted to the Nongame Wildlife Program, Minnesota Department of Natural Resources. 22 pp.
OBJECTIVE: 1) To determine the presence of rock voles on sites where they were and were not trapped in 1982. 2) To compare the responses of rock voles to different types of traps. 3) To determine basic aspects of rock vole social structure. 4) To make recommendations about the monitoring of rock vole populations. METHODS: Traps were set at 23 sites where Christian (1982) secured rock voles in 1982 and at 3 additional sites. Each site was trapped with 25 live traps and 25 snap traps. Pit traps were also set. Most trap lines were set between 1300 and 1800 hours. Lines were checked daily between 0900 and 1200 hours and were left out for four days. RESULTS: Rock voles were taken at 19 of the 23 sites where they had been secured in 1982. No voles were taken at site J1. Of the total 121 Rock voles taken in samples and recapture areas, 60% were males, 40% were females. 22% of the males had scrotal testes and at least 31% of the females were parous or nulliparous pregnant.