By Shannon Bohman ’19
Most mammals are endothermic, meaning they generate their own body heat. Some creatures, called ectotherms, are unable to self-sustain a body temperature above the surrounding temperature. However, researchers at the University of Alberta in Canada and the University of Melbourne in Australia have found a particular ectotherm, the tegu lizard, that often displays endothermic characteristics. During their reproductive season, tegu lizards maintain an overnight bodily temperature well above the ambient temperature. Despite being ectotherms, these lizards can elevate their metabolic rates to produce and trap extra body heat. This may be a means of enhancing reproductive success. These seasonally endothermic lizards have expanded scientists’ theories on the evolution of true endotherms, such as mammals and birds. Additionally, these findings support the evolutionary advancement in the study of endotherms that can help animals nurture their offspring.
- Image acquired from: http://www.tampabay.com/resources/images/dti/rendered/2014/07/tegulizard_13593718_8col.jpg
- Tattersall et al., Seasonal reproductive endothermy in tegu lizards. Science Advances (2016).