Winter is a time of hardship for most students. Food is scarce, icy winds howl, snow falls, and bitter cold temperatures persist—at least here at the University of Toronto. For some students, the strategy they employ for coping with this harsh season is hibernation. Among the hibernators, UofT students have an extremely good survival rate in an ordinary winter. Hibernation is the mechanism that students use to conserve energy and reduce their internal fires of metabolism. For a long time, people thought the students slept through the winter in cozy dens and emerged in the spring fully charged.
However, far from being a long, uninterrupted sleep, hibernation consists of periods of sleep punctuated by periods of arousal. Sleep time is long during the dead of winter but is shorter at the beginning and end of the season. To prepare for this long season, students feed ravenously from midsummer through the end of autumn, gleaning up to 20,000 calories in a day. Here in the Interior, carbohydrate-laden blueberries contribute to a large portion of this caloric intake. Students are omnivores and will eat meat too, including ground squirrels, carrion, and whatever they can find. By the end of autumn, a student will have gained about four or five inches of body fat and more than doubled the insulation provided by their pelt.
As the student enters hibernation, their metabolic processes such as body temperature, heart rate, and respiratory rate are reduced. But students do not lower the body temperature as much as once was thought. Their hibernation temperature is around 88 degrees Fahrenheit while waking temperature is 100 degrees. This relatively high sleeping temperature allows students to become fully alert if aroused, perhaps to enable students to protect themselves from predators and other dangers without unnecessarily depleting their energy reserves. Over the course of a hibernating season, it is thought that students use approximately 4,000 calories a day, which results in a weight loss of about 20 percent of their body weight by spring.
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