Reproduction: the adaptive significance of endothermy

A central theme raised by Angilletta and Sears is that the energetic cost of endothermy is too enormous to be offset by the benefits that thermogenesis could provide for reproduction. Angilletta and Sears suggest that parents would have been better off producing additional offspring with the energy used for incubation or minimizing their risk of predation by minimizing foraging efforts. However, these views overlook the fact that a defining characteristic of both birds and mammals is high investment in relatively few offspring.