2007 Volume 12 Issue 1 Pages 35-39
It is considered that global warming and exposure to endocrine disrupting chemicals can influence reproduction and hibernation of wildlife. However, environmental factors responsible for such behavioral differences are not well recognized. Therefore, in this study we analyzed environmental conditions that are critical for inducing hibernation. Non-seasonal hibernators, Syrian hamsters were used in this study. It has been pointed out that a low environmental temperature is an important factor to induce hibernation. So, hamsters were kept at a cold room. After about two or three months, they hibernated. Next, food restriction under the cold environment was performed. When the hamsters were fed sunflower seeds or high fat food not standard laboratory chow and then food supply was restricted, they efficiently hibernated in a shorter time period compared with those which were given free access to food. This suggests that the quantity and nutritional composition of food can affect hibernating behavior in addition to a low environmental temperature. We noticed that hibernation is more efficiently induced in obese hamsters than in thin ones. This may indicate that hormones derived from adipose tissue including leptin could be related to hibernation. These results suggest that hibernation might be associated with external environmental factors (environmental temperature and food composition).