image: Electrocardiogram (ECG) showing the regular heart beat pattern of a black bear in summer (top) and the slow, irregular heart beat pattern during hibernation (bottom). During hibernation the heart slows with as much as 20 seconds between beats. Each time the bear takes a breath, about 1-2 times per minute, the heart beats more rapidly. This image relates to an article that appeared in the Feb. 18, 2011, issue of Science, published by AAAS. The study, by Dr. Øivind Tøien, at the University of Alaska Fairbanks, and colleagues was titled, "Hibernation in Black Bears: Independence of Metabolic Suppression from Body Temperature." view more
Credit: [Image courtesy of <i>Science</i>/AAAS]