The Mississippi Valley Field Naturalists November Nature Talk was entitled “Life in Limbo” or “The Living Dead and the Control of Biological Time”. Dr. Ken Storey provided a lively and entertaining talk about hibernation. Ken is a Professor of Biochemistry at Carleton University and holds the Canada Research Chair in Molecular Physiology. Ken’s field of interest is biochemical adaptation; in particular, mammalian hibernation and freeze tolerance are core topics in his over 1000 refereed publications.
Ken began by explaining that hibernation is a state of minimal activity and metabolic depression. His studies are particularly interested in understanding the processes involved and learning how they can be applied to humans. For example, this knowledge could be used for astronauts during deep space exploration. In the case of ground squirrels it has been found that while hibernating: their muscles don’t atrophy, their hearts are stronger, they become insulin-resistant but don’t develop diabetes and there is a suppression of cell growth such that tumors do not grow. A better understanding of these processes is useful in medical studies, including the possibility of room temperature transplantation of organs.
Hibernation functions to conserve energy when sufficient food is not available. Ken gave the example of lemurs which live in warm climates but hibernate in the dry season due to food shortages. He explained the various types of hibernation, including aestivation, anoxia, freezing and diapause. His research is directed towards understanding the technical mechanisms involved. Many animals do not truly hibernate but enter torpor. Ken explained that this is a state of decreased physiological activity in animals. It is generally marked by a reduced body temperature and metabolic rate and can last from hours to weeks. Ken concluded with some specific examples: crocodiles can dry themselves out although not for a long period of time, goldfish convert carbs to ethanol so that they can survive in a low oxygen environment, garter snakes can freeze but will thaw on warm days, chipmunks cache food but will hibernate if all their food is gone, and other examples.
There is no Nature Talk in December, but we will be back on January 18, 2024 with Dr. Catherine Scott and “The Secret Lives of Spiders”.
Submitted by Chris Baburek