AP BIOLOGY

Detailed explanation-1: -Endothermic animals are animals that are able to maintain a constant body temperature regardless of their ambient temperature. Endothermic animals include all birds and mammals of the animal kingdom. Even some fish are considered to be endothermic.

Detailed explanation-2: -Birds are endothermic, and because they fly, they require large amounts of energy, necessitating a high metabolic rate. Like mammals, which are also endothermic, birds have an insulating covering that keeps heat in the body: feathers.

Detailed explanation-3: -Mammals and birds are the classical model for endothermic vertebrates, and as such, the occurrence of thermogenic strategies in other clades is often overlooked.

Detailed explanation-4: -Reptiles and amphibians are ectotherms, while birds are endotherms. An ectotherm (reptile/amphibian) relies primarily on its external environment to regulate the temperature of its body. Endotherms (birds) are able to regulate their body temperatures by producing heat within the body.

Detailed explanation-5: -Like mammals, birds are endothermic, or warm blooded, but they are the only animals that have feathers.