Hibernation is a way for bears to conserve energy in the winter when food is in low supply. However, most bears do not go into hibernation in warm climates where enough food is available year-round. During a period called hyperphagia, bears prepare for hibernation by eating three times as much in the fall as they do in the summer. In the fall, bears need up to 20,000 calories per day (about 300 apples) to gain enough weight to get through the winter. In some areas, food-conditioned bears that are used to accessing human food, such as garbage, may not hibernate at all.
Most black bears and grizzly bears den for four to six months in the winter, from November or December until March or April. Bear cubs are born in the den during this period. However, bears do not go into true hibernation because their body temperature and metabolic rate do not decrease as much as in other hibernating species and they may wake up relatively easily during their winter sleep. In order to survive without eating, bears must slow down their physiological systems and live off their fat reserves. They actually enter a state of dormancy where:
• their heart rate drops from 40-70 beats per minute to 8-12 beats per minute;
• their metabolism slows down by half and
• their body temperatures by drop by 3-7 degrees Celsius.
While bears do not eat or drink during this time, they do not urinate or defecate either. Such a build-up of urea would cause humans to die. Bears however, have a unique ability to recycle the build-up or urea, using its constituents to manufacture new proteins. During hibernation, the bear’s body essentially enters a mode of conservation, efficiency and recycling.
Finally, the WildSafeBC Fernie and Elk Valley Programs wish to thank program sponsors; The British Columbia Conservation Foundation, Ministry of Environment, Columbia Basin Trust, City of Fernie, District of Elkford and the R.D.E.K. for their ongoing financial support and everyone who has made an effort to prevent wildlife/human conflict in the Elk Valley and South Country.
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