In general, cold-blooded animals are those whose body temperature is regulated by the environment, and warm-blooded animals are those capable of maintaining relatively constant body temperature through internal regulatory mechanisms ( thermoregulation ).
But these concepts of cold-blooded or warm-blooded animals can be misinterpreted. A cold-blooded animal does not have to have necessarily cold blood, only it depends on the environment and cannot regulate it by itself.
The most precise terms refer to the thermoregulation mechanisms used:
- Warm-blooded animals: also called endotherms, they have thermoregulatory mechanisms through endotherm, homeothermic and track metabolism
- Cold-blooded animals: also called poikilotherms or ectotherms have mechanisms of thermoregulation through ectothermic, poikilothermia and brand metabolism.
Examples of cold-blooded and warm-blooded animals
The vast majority of mammals, including man, and birds are warm-blooded.
Cold-blooded are reptiles, fish, insects, amphibians, and arachnids. But there are exceptions, even animals that show characteristics of both types.
For example, bats and mole-rats are mammals, but their body temperature may depend on the environment, especially when they are inactive.
Some insects, such as the hawk moth and some types of bees, can increase your body temperature if they need to by flapping their wings.
Also, some fish have internal mechanisms to keep parts of their bodies warm, such as eyes and brains, and to prevent their temperatures from dropping too low and being damaged.
Warm-blooded animals need more food
Staying warm costs energy and energy is derived from nutrients provided by food, so warm-blooded animals generally need more food to survive.
For this same reason, endothermic animals have to be better at obtaining food, which places them on a different metabolic and evolutionary level.
Ectothermic animals rely on external sources of heat, such as sunlight, instead of creating this heat themselves. This is why reptiles “bask in the sun” and therefore need less food consumption.
Advantages and disadvantages of being an endotherm or ectotherm
In general, endothermic animals have numerous evolutionary advantages over cold-blooded animals. The main and most important is that they maintain the temperature around the levels in which your body works optimally. All chemical reactions involved in processes such as thinking, moving, digesting food, etc., are carried out under optimal conditions.
By contrast, cold-blooded animals must maintain multiple biochemical systems that work at different temperatures, even if it does not do so optimally. From an evolutionary point of view, this is considered a clear disadvantage, but it allows cold-blooded animals to not have to spend energy to maintain the temperature and therefore need less food, which is a survival advantage over animals of warm blood in situations of food shortage.