2011/02/17 by Øivind Tøien, John E. Blake, Dale M. Edgar +3 · 477 citations
Agricultural and Biological Sciences · Chemistry · Environmental Science · Mathematics · #Animal science #Bat Biology and Ecology Studies #Biology #Chemistry #Effects of Environmental Stressors on Livestock #Endocrinology #Hibernation (computing) #Homeothermy #Human body temperature #Independence (probability theory) #Mathematics #Metabolic rate #Physiological and biochemical adaptations #Physiology #Statistics #Thermoregulation
paper · doi:10.1126/science.1199435
published in Science 331(6019), 906-909 (American Association for the Advancement of Science)
openalex publication_date 2011/02/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Black bears hibernate for 5 to 7 months a year and, during this time, do not eat, drink, urinate, or defecate. We measured metabolic rate and body temperature in hibernating black bears and found that they suppress metabolism to 25% of basal rates while regulating body temperature from 30° to 36°C, in multiday cycles. Heart rates were reduced from 55 to as few as 9 beats per minute, with profound sinus arrhythmia. After returning to normal body temperature and emerging from dens, bears maintained a reduced metabolic rate for up to 3 weeks. The pronounced reduction and delayed recovery of metabolic rate in hibernating bears suggest that the majority of metabolic suppression during hibernation is independent of lowered body temperature.