Meeting Abstract

13.7  Friday, Jan. 4  Reproduction and the evolution of endothermy-Increased homeothermy in reproductively active female Greater hedgehog tenrecs (Setifer setosus) LEVESQUE, D.L.*; LOVEGROVE, B.G.; University of KwaZulu-Natal; University of KwaZulu-Natal

There is increasing evidence that the level of homeothermy observed in most modern endotherms was derived from an ancestral heterothermic state. One of the hypotheses for why this occurred is that homeothermy allows for greater energetic output during reproduction (gestation and lactation) which has direct benefits to fitness. We tested this hypothesis by recording free-ranging body temperatures as well as resting metabolic rate over a range of ambient temperatures in both reproductive and non-reproductive Greater hedgehog tenrecs (Setifer setosus, Tenrecidae), a physiologically primitive mammal from Madagascar. During pregnancy and lactation there was an increase in metabolic rate and body temperature, accompanied by a decrease in body temperature variability. This indicates that homeothermy accompanies reproduction, and that benefits to parental care may have contributed to the evolution of endothermy in mammals.