Breeding, abundance and population structure of the Bank vole Clethrionomys glareolus (Schreber, 1780) in the western Pyrenees

Abstract

The reproductive cycle of a population of Bank voles (Clethrionomys glareolus) in the western Pyrenees was related to the population structure over a two-year period and compared to other European populations. There were rnarked differences in the length of the reproductive season between the two years. Breeding began at the end of the winter and reached its highest rate during the auturnn of the first year. In the second year the breeding did not cornrnence until surnrner. The average litter size was similar to that previously reported in the north of the lberian peninsula and France, although it varied with time. Changes in litter size were related to the age of reproductive fernales.