Winter breeding in three rodent species, the bank vole Clethrionomys glareolus, the yellow-necked mouse Apodemus flavicollis and the wood mouse Apodemus sylvaticus in southern Sweden

Winter breeding, as judged from heavy reproductive organs in both males and females, was observed in bank voles, yellow-necked mice and wood mice in south Sweden during the winter of 1976–1977. The breeding was probably a result of unusually favourable feeding conditions created by an extremely rich beech mast crop.