A lab contribution published last week investigates the ecological implications of metabolic resilience at cold temperatures for salamanders. This research combined field measurements of environmental and body temperatures of field active European fire salamanders, including of animals walking on snow (see pictures and video) taken with infrared cameras, with laboratory measurements of heart rate (a proxy for aerobic metabolism) dependency on body temperature. Salamanders were only active at low to moderate temperatures not exceeding 16C, and although heart rate initially decreased linearly as temperatures were lowered, starting at 8C such rate of decrease became increasingly smaller such that at near freezing temperatures salamanders still had heart rates similar to those recorded at body temperatures of 6-8C. Winters, when fire salamanders are mostly active, are becoming warmer and shorter, and the increasing number of days of above-freezing temperatures will allow greater opportunities for field activity - and thus greater energetic demands for these animals.
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