Once awoken, what happens to the Black Bears?
Researchers studied a species of hibernating black Bears. Each year the Black Bears go into hibernation for a 5-7 month period. During this time, they do not consume any food. Researchers explored the metabolic processes that allow black Bears to survive for so long without eating.
Figures adapted from Hibernation in Black Bears: Independence of Metabolic Suppression from Body Temperature by Oivind Toien et al.
Researchers gathered black Bears and transported them to facilities in Alaska where they were placed in wooden box habitats. The researchers prepared to measure the Black Bears core body temperature and oxygen consumption during hibernation. Core body temperature was measured through implanted radio transmitters, and oxygen consumption was measured through the constant collection and analysis of air in the habitat. EMG was also surgically implanted to measure electrical activity. Results representative of a typical six-day period during hibernation can be observed in Figure 1.
Researchers had additionally installed devices to track the hibernating Black Bears movements including infrared cameras. Once awake, the researchers continued to analyze the Black Bears metabolisms to better understand the process of recovering from hibernation. After having done so, the researchers decided to graph the last several months of hibernation and the post hibernation period, as can be seen in Figure 2. The legend indicates different individual Black Bears. The dashed line indicates the average date the Black Bears woke up from hibernation.
(A) Once awoken, the average oxygen consumption of Black Bears increases. In all three Black Bears oxygen consumption increases significantly upon awakening. It does not decrease or remain the same, and average core body temperature does not decrease for any of the three Black Bears.