WIKIMEDIA, BJORN CHRISTIAN TORRISONThe Argentine black and white tegu (Salvator merianae) is unique among its reptilian kin, according to researchers who recently confirmed that the lizard can regulate its body temperature, in some seasons raising it a full 10°C above its surroundings. The tegu’s feat of endothermy is special among the typically ectothermic Class Reptilia—only a few other species are known to purposefully alter their body temperatures above that of the surrounding environment, and none achieve such a dramatic difference.
Researchers from Canada and Brazil reported last week (January 22) in Science Advances that tegu lizards behave like other reptiles for most of the year—sunning themselves to stay warm during cold periods and seeking shade to lower their body temps—but act more like endotherms, such as birds and mammals, during their mating season (September to December). In the coldest, early morning hours of that season, the tegu can produce heat sufficient to warm its body about 10°C above its surroundings. “We would expect them to be as cold as they possibly could be at that time,” study coauthor Glenn Tattersall of Brock University in Canada told New Scientist.
Although Tattersall and his colleagues could not pinpoint a physiological mechanism that allows the tegu to produce ...
