Reproduction strategy in an island population of yellow-necked mice

A population of yellow-necked mice, Apodemus flavicollis, inhabiting Crabapple Island (NE Poland) was sampled from 1994–2002. The catch-mark-release method was applied. Sexually mature males and females (including pregnant ones) as well as immatures of each sex were identified. During the study period 3,036 mice were caught 10,672 times. The number of mice caught varied from 6 individuals (April 1999) to 272 (July 1996). The number of both mature females and mature males increased linearly with population size. Differences in the reproductive strategies of yellow-necked mouse and bank voles, Clethrionomys glareolus, are discussed. The respective strategies led to high variability in the population size of mice and much less variability in the case of the voles during the breeding season.