Influence of fattening food type on the birthing period in the edible dormouse

In communities characterized by periodic pulses of food availability, the relationship between resource peaks and the timing of reproduction among consumers is of paramount importance for the survival of offspring. In certain instances, they may give birth to juveniles well before the peak of food availability, prioritizing optimal conditions for juveniles over mature females. The species that can cope with masting periods in temperate broad-leaved forests through different reproductive mechanisms is the edible dormouse. It can start reproduction long before the maturation of the main types of fattening foods – beech nuts or acorns. During this study, in an oak-dominated forest in the years when acorns are almost absent, dormice exhibited anticipatory reproduction in response to an alternative food source: hazelnuts. Through precise tracking of food availability during the early stages of maturation, dormice reproduced long before the ripening of nuts in mast years. Surprisingly, parturition occurred even earlier than during years with abundant acorn crops. No significant differences in litter size were observed. The nutritional value of hazelnuts for successful reproduction was indirectly validated through amino acid analyses of both food types. Any amino acid peculiar for any seeds or its extreme content was not found. Content of some of them was even higher in the nuts. This synchronization of the growth of offspring with seed ripening ensures maximal food abundance when litters disperse, a time when juveniles are most vulnerable.