The above relations hold for the homeothermic mammals, those with nearly constant body temperature.
Bats of several tropical families maintain a constant body temperature (homeothermy).
"What I am doing is creating this constant body of work — a way of understanding the world".
The first true mammals probably had a mix of warm-blooded, constant body temperature interspersed with daily, or even seasonal, torpor or hibernation.
Gradually, he said, he became numb to the constant body count -- crushed hands and feet, disfiguring lacerations, burns from molten iron, amputations.
The second group, the homoiotherms, maintain a constant body temperature regardless of the ambient temperature; these warm-blooded animals include birds and mammals.
In warm-blooded animals, for example, the heat released by muscles maintains a constant body temperature regardless of the environmental temperature.
More than that, as a marine mammal Livyatan would have maintained a high, constant body temperature, and therefore would have required an enormous amount of energy to fuel its body.
These snakes feed almost exclusively on animals, such as birds and mammals, that maintain a constant body temperature and can therefore be located by the snake through the reception of the heat of the warm body.
In contrast to reptiles and fish, which are cold-blooded (poikilothermic) and regulate their body temperature mainly behaviorally, mammals are warm-blooded (endothermic) and maintain a constant body temperature (homeothermic) using active neural, physiological, and behavioral processes.
The hallmarks of the mammalian level of organization are advanced reproduction and parental care, behavioral flexibility, and endothermy (the physiological maintenance of a relatively constant body temperature independent of that of the environment, allowing a high level of activity).
