Difference Between Cold Blooded and Warm Blooded Animals

Main Difference – Cold Blooded vs Warm Blooded Animals

Organisms can be classified into two broad categories based on the ability to regulate body temperature with the surrounding temperature: these two categories are cold-blooded (ectotherms) and warm-blooded (endotherms) animals. The main difference between cold blooded and warm blooded animals is that the cold-blooded animals cannot maintain a constant body temperature, whereas warm-blooded animals can maintain a constant body temperature. Because of this reason, their body shows various adaptations to regulate temperature with respect to their surrounding temperature. The difference between cold and warm blooded animals will be discussed in more detail in this article.Difference Between Cold Blooded and Warm Blooded Animals - infographic

What are Cold Blooded Animals

Cold-blooded animals or ectotherms are the organisms that regulate their temperature at a constant level with the changes in the surrounding temperature. The activities of these creatures are greatly affected by the surrounding temperature since the metabolic rate depends directly on the body temperature. Generally, activity decreases when the surrounding temperature decreases and vice versa. Metabolic rate is mainly regulated by heat or energy gain from the environment rather than by energy generated inside their body. Because of this reason, most of the cold-blooded animals are found in warm habitats. Animals that live in cold habitats are usually sluggish. Cold-blooded animals show various adaptations to increase their body temperature, such as bathing in the sun, changing the body colors, stretching out limbs under sunlight, etc. During the very cold season, cold blooded animals become very inactive. For example, certain frog species and salamanders do not move during the winter season, and most insects do not fly until the temperature of the flight muscles increases to an optimum temperature. Many animals, especially the vertebrates such as amphibians, reptiles and fish are cold-blooded animals.

Difference Between Cold Blooded and Warm Blooded Animals

Thermographic image of a snake (cold blooded) eating a mouse (warm blooded)

What are Warm Blooded Animals

Warm-blooded animals are also known as endotherms, which means that they can produce their own body temperature despite the environmental temperature changes. They maintain a constant body temperature between 35 – 40 °C mainly by metabolic processes and adaptive mechanisms such as sweating, panting, insulation, regulation of blood flow to extremities, migration, hibernation, burrowing, changing the body surface area to body volume ratio, etc. Because of these mechanisms,warm blooded animals are extremely adaptive and can live within a wide range of environmental temperatures from freezing arctic to hottest deserts. Therefore, warm-blooded animals are found almost all the habitats in the world. Mammals and birds are the only groups of warm-blooded animals. When compared to cold-blooded animals, warm-blooded animals have very high energy expenditure due to their high metabolic rates.

Main Difference - Cold Blooded vs Warm Blooded Animals

Sustained energy output of a warm blooded animal (mammal) and a cold blooded animal (reptile) as a function of core temperature

Difference Between Cold Blooded and Warm Blooded Animals

Definition

Cold blooded animals: Cold blooded animals cannot maintain a constant body temperature.

Warm blooded animals: Warm blooded animals can maintain a constant body temperature.

Energy Production

Cold blooded animals: Cold blooded animals always gain energy in the form of heat to regulate body heat.

Warm blooded animals: Warm blooded animals can produce heat within their body.

Heat Source

Cold blooded animals: Cold blooded animals obtain heat through the surrounding environment.

Warm blooded animals:Warm blooded animals generate heat mainly through consumption of food.

Metabolic Rates

Cold blooded animals: The metabolic rates of cold blooded animals always change with changing environmental temperature. Metabolic rates of cold-blooded animals are usually low than that of warm-blooded animals.

Warm blooded animals: In general, environmental temperature does not greatly affect the body heat of warm-blooded animals.

Body Temperature

Cold blooded animals: The body temperature  of cold blooded animals varies with surrounding temperature.

Warm blooded animals: The body temperature of warm-blooded animals is usually between 35-40 °C.

Heat Regulation

Cold blooded animals:Cold-blooded animals regulate heat by various methods including bathing in the sun, changing the body colors, stretching out limbs under sunlight, etc.

Warm blooded animals: Warm-blooded animals regulate heat mainly by metabolic processes and adaptive mechanisms such as sweating, panting, insulation, regulation of blood flow to extremities, migration, nocturnally active, hibernation, burrowing, changing the body surface area to body volume ratio, etc.

Examples

Cold blooded animals: Fish, reptiles, amphibians, insects, etc. are examples of cold blooded animals.

Warm-blooded animals: Mammals and birds are examples of warm blooded animals.

Image Courtesy:

“Wiki snake eats mouse” By Arno / Coen – www.nutscode.com (CC BY-SA 3.0) Commons Wikimedia

“Homeothermy-poikilothermy” By Petter Bøckman – Own work (Public Domain) via Commons Wikimedia 

About the Author: Yashoda

Yashoda has been a freelance writer in the field of biology for about four years. He is an expert in conducting research related to polymer chemistry and nano-technology. He holds a B.Sc. (Hons) degree in Applied Science and a Master of Science degree in Industrial Chemistry.