The Spring Decline in Populations of the Bank Vole, Clethrionomys glareolus, and the Role of Female Density

Publisher Website
Google Scholar
Abstract
The role of female density in the spring decline of the bank vole, C. glareolus (Schreber), was studied on 2 experimental and 2 control plots in southern England between Nov. and April in 1980-1981, and between Nov. and June in 1981-1982. Artificial reduction in female population density by .apprx. 50% at the beginning of Feb. on experimental areas resulted in a lower rate of decline in the numbers of both sexes than on control areas. In both years, the experimental reduction in female numbers was done .apprx. 9 wk before the start of the breeding season. In 1980-1981, population monitoring finished just when animals started coming into breeding condition. In 1981-1982, monitoring continued for .apprx. 3 mo. into the breeding season, until animals were being recruited into the trappable population; in this year, there were no differences in the proportions of males and females in breeding condition between experimental and control areas. Immigration onto all areas was slight, with no differences between experimental and control areas. Both males and females survived better on the experimental areas than on the control areas. The role of female spacing behavior in the regulation of vole populations is discussed.