Seasonal Reproduction in the Meadow Vole

Abstract

Population structure and reproductive condition of the meadow vole, Microtus pennsylvanicus, were analyzed for the period of July 1954 through July 1955. During this period there was a heavy snow cover throughout the winter and breeding was recorded for every month of the year. In the winters of 1954–55 and 1960–61, when there was very little snow cover, breeding ceased by 17 November and did not resume until about 20 March. From the 1954–55 period, 1,084; in the 1957–58 period, 37; and in the 1960–61 period, 217 meadow voles were examined.