Chapter 28, Animal Systems II - Assessment - 28.4 Homeostasis - Understand Key Concepts/Think Critically - Page 836: 31

Ectothermy is advantageous for organisms that live in warm environments that are fairly constant. The advantages of ectothermy are that ectothermic organisms do not need as much food as an endothermic one of the same size; however, ectothermic animals cannot live in colder environments. Endothermy is disadvantageous because endothermic animals need more food than their ectothermic counterparts of the same size; however, endothermic animals do not rely on the environment to heat their bodies, so they are able to live either in cold or warm climates.

Ectothermy is advantageous for organisms that live in warm environments that are fairly constant. The advantages of ectothermy are that ectothermic organisms do not need as much food as an endothermic one of the same size; however, ectothermic animals cannot live in colder environments. Endothermy is disadvantageous because endothermic animals need more food than their ectothermic counterparts of the same size; however, endothermic animals do not rely on the environment to heat their bodies, so they are able to live either in cold or warm climates.