Freeze Avoidance in a Mammal: Body Temperatures Below 0°C in an Arctic Hibernator

• Published in: Science
• Main Author: Barnes, Brian M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1989
• Subjects: Arctic; Burrows
• Online Access: http://dx.doi.org/10.1126/science.2740905; https://www.science.org/doi/pdf/10.1126/science.2740905

Hibernating arctic ground squirrels, Spermophilus parryii , were able to adopt and spontaneously arouse from core body temperatures as low as -2.9°C without freezing. Abdominal body temperatures of ground squirrels hibernating in outdoor burrows were recorded with temperature-sensitive radiotransmitter implants. Body temperatures and soil temperatures at hibernaculum depth reached average minima during February of -1.9° and -6°C, respectively. Laboratory-housed ground squirrels hibernating in ambient temperatures of -4.3°C maintained above 0°C thoracic temperatures but decreased colonic temperatures to as low as -1.3°C. Plasma sampled from animals with below 0°C body temperatures had normal solute concentrations and showed no evidence of containing antifreeze molecules.