Changes in body mass of postweaning juveniles of the edible dormouse, Glis glis (L.), in captivity

Abstract

Edible dormice have to accumulate an adequate amount of body fat before hibernation. Because young dormice are born late in the season, they have a relatively short time for prehibernation fattening. The aim of our study was a) to determine what body mass juveniles reach prior to hibernation, and b) to examine patterns of mass gain in juvenile dormice with unlimited food supply. Dormice were kept in outdoor cages, fitted with wooden boxes and with the floor covered with soil suitable for hibernation. They were provided with water and fed ad libitum. They were weighed every 5-8 days. Of 34 juveniles (17 males and 17 females; 26 born in captivity and 8 caught in the wild), 22 began hibernation in underground cavities. The mean body mass of juveniles prior to hibernation was 89.7 $\pm$ 14.8 g. The mean daily mass gain was 0.82 g. The range of mass change varied from -4.00 to 5.71 g/day. Wild-caught juveniles most quickly gained mass during the first week in captivity with a mean rate of 4.54 g/day. We found that prior to hibernation body mass of juvenile dormice was lower than it was expected according to the literature. We show that fluctuations of body mass can be high, even in a short period of time.