Heterothermy in large mammals: inevitable or implemented?

摘要: Advances in biologging techniques over the past 20 years have allowed for remote and continuous measurement of body temperatures free-living mammals. While there is an abundance literature on heterothermy small mammals, fewer studies investigated daily variability core temperature larger Here we review measures factors that influence large mammals their natural habitats, focussing mammalian herbivores. The mean 24 h 17 species herbivores (>10 kg) decreased by ∼1.3°C each 10-fold increase mass, a relationship remained significant following phylogenetic correction. degree heterothermy, as measured amplitude rhythm, was independent mass appeared to be driven primarily energy water limitations. When faced with competing demands osmoregulation, acquisition or use thermoregulation, appear relax precision thermoregulation thereby conserving energy. Such relaxation may entail cost animal moves closer its thermal limits performance. Maintaining homeostasis requires trade-offs between regulated systems, homeothermy apparently not accorded highest priority; are able maintain optimal only if they well nourished, hydrated, compromised energetically. We propose rhythm provides useful index any compromise experienced mammal predict performance fitness animal.