Local environmental factors affect reproductive investment in female edible dormice

Abstract

Edible dormice (Glis glis) are exposed temporally and spatially to a tremendous variation in food resources. This variation strongly influences reproduction; in edible dormice reproduction is tightly linked to the availability of energy-rich seeds. Although most dormice reproduce in full mast years of beech or oak, entire populations skip reproduction in years without seed production; however, nearly 50% of all years are intermediate mast years, during which only part of the dormouse population reproduces. We investigated how the beech mast pattern, local habitat characteristics, and individual traits (body mass and age class) influence whether individual female edible dormice invest in reproduction in intermediate mast years. Our field study, conducted during 2006–2009 in the Vienna Woods, revealed that in intermediate mast years the probability of females reproducing increased with the age of trees but not with the proportion of beech trees within their home ranges. Mean litter size was larger in years with higher seed availability and also increased with the mean age of trees within the home range of the dormice. More adult than yearling females reproduced, but this effect was modulated by yearly and local variation in food availability. Whether a female edible dormouse reproduces in an intermediate mast year depends mainly on the local food availability and age of the individual.