Are Birds Warm Blooded Or Cold Blooded?

Birdlife is found in habitats as diverse as the hottest, driest deserts to frozen Arctic tundra landscapes. Birds can adapt to surviving in extreme temperatures, as well as being able to live in regions where the climate is more unpredictable.

Read on to find out how a bird’s physiology prevents it from freezing to death when temperatures drop, as we explore the question: are birds warm blooded or cold blooded?

Birds are warm blooded. Their body temperature is controlled by a metabolic reaction in a portion of the brain known as the hypothalamus. This allows birds to use the energy from the food they eat to control their own body temperature, regardless of whether it’s hot or cold outside.

There are no cold-blooded birds; without exception, all avians are endothermic (another word for warm blooded). This is in contrast to exothermic (cold-blooded) animals, like most reptiles, which rely on their external environment to regulate their body temperature.

A cold-blooded animal’s internal temperature always matches their current environment, while warm-blooded birds regulate their own temperature using a number of different methods.

Keep reading to learn more about some of these adaptations, as we take a look at the evolution of birds and investigate whether they have always been warm blooded or whether they evolved from cold-blooded ancestors.

All types of birds are warm blooded

All types of birds are warm blooded

Why are birds warm blooded?

Birds regulate and control their own body temperature so that it is constantly within a certain range.

All bird species have a body temperature range higher than that of a human; this needs to remain at a constant level of between 41 and 43 degrees Celsius (106 to 109 degrees Fahrenheit) for a bird to be in good health. Birds are adapted to use techniques to warm themselves up in cold weather and cool down when temperatures rise.

Birds are classed as warm blooded as they turn the energy gained from eating food into the vast reserves that are needed to constantly maintain their body temperature. All birds have a high metabolic rate, needing to eat regularly to ensure this internal chemical reaction needed to stabilize their body temperature can take place.

Birds are adapted to use techniques to warm themselves up in cold weather and cool down when temperatures rise

Birds are adapted to use techniques to warm themselves up in cold weather and cool down when temperatures rise

How does it help birds to be warm blooded?

As warm-blooded creatures, birds are able to maintain a stable core body temperature, rather than responding purely to the environment in which they live. This helps birds to survive in a range of climates and to remain active in extremely cold temperatures.


Birds do not have the ability to sweat so in extremely hot weather, they have developed other adaptations to reduce excess body heat, for example by panting or opening their beaks wide to increase the amount of hot air they are breathing out.

Birds are adapted to cope with extreme cold, too, preserving body heat when needed by fluffing up their feathers and trapping layers of warm air close to their skin. By being able to regulate their own temperatures to stay warm in winter, birds avoid freezing to death when the temperatures plunge.


The circulation of warm blood around birds’ bodies and legs allows them to stand on ice with their feet at subzero temperatures while their body's core temperature remains stable.

Birds need to be able to survive in places like the Arctic. One of the places Gyrfalcons breed, is on Arctic coasts and tundra

Birds need to be able to survive in places like the Arctic. One of the places Gyrfalcons breed, is on Arctic coasts and tundra

Are all birds warm blooded?

All birds are warm blooded, just like all mammals. This means that they must regulate their own body temperature to remain at a constant level, no matter what the external climate or weather conditions.

Birdlife exists in arid deserts (ostriches, emus), frozen expanses of Antarctica (penguins), tropical rainforests (parrots, parakeets), and exposed heathland with little protection from the elements (grouse).

With the need to survive in such a diverse range of habitat extremes, all bird species share the ability to stabilize their own body temperatures.

Being warm blooded helps birds survive in a extreme range of habitats

Being warm blooded helps birds survive in a extreme range of habitats

Have birds always been warm blooded?

One major current research theory supports the evolution of modern-day birds from a group of theropod dinosaurs. Current studies believe these to have been warm-blooded creatures, rather than cold-blooded ones, as was once widely believed.

The reasoning behind this hypothesis comes from studying fossilized remains of the ancient bird-like theropods, which were covered with hair and soft downy feathers, findings which support the theory that these dinosaurs were adapted to be able to control and conserve their own body heat.

Simply put, birds have always been warm blooded and originally descended from a group of warm blooded dinosaurs.

Birds have always been warm blooded

Birds have always been warm blooded

When did birds become warm blooded?

Birds are believed to have evolved from a group of theropod dinosaurs, which were characterized by hollow bones and three-toed limbs. The current consensus among paleontologists is that this group of dinosaurs were warm blooded.

The evolution of birds can be traced to the clade of dinosaurs known as Maniraptora, which lived during the Jurassic period. Since the earliest point in their evolution, birds have always been warm blooded. They were never cold blooded.

Current research suggests that birds’ warm-bloodedness may be linked to the development and evolution of the need to fly. The dinosaur group that birds evolved from had some feathers but were not capable of flight.

With the ongoing evolution of smaller creatures with fully developed feathers that could eventually sustain flight, maintaining a constant body temperature became necessary for survival in different environments.

This mutation developed during the course of hundreds of thousands of years, giving birds the evolutionary advantage of flight and the survival benefits as warm-blooded beings in a world with a variety of different climates to contend with.

Birds' warm-bloodedness may be linked to the development and evolution of the need to fly

Birds' warm-bloodedness may be linked to the development and evolution of the need to fly

FAQs

Are all birds cold blooded?

All bird species are warm blooded. There are no cold-blooded birds. A bird’s average body temperature is higher than that of a human, at a constant level of between 41 and 43 degrees Celsius (106 to 109 degrees Fahrenheit), and birds have different methods of adapting to conserve or reduce their body heat depending on the weather conditions.

Are penguins cold blooded?


Penguins, like all birds, are warm blooded, and this is what enables them to survive in the extremely low temperatures in their natural Antarctic habitats. All penguin species can maintain, adapt, and stabilize their own body temperature, even in the coldest climates, helped by a layer of fat deposits under their skin that is known as blubber. This blubber keeps a penguin warm, alive and active in some of the most bleak landscapes on Earth.

Expert Q + A

Ask a question

Do you have a question about this topic that we haven't answered? Submit it below, and one of our experts will answer as soon as they can.

Include your email address to get a message when this question is answered.

You may also like

Get the good stuff

Get the latest BirdFacts delivered straight to your inbox

© 2022 - Bird Fact. All rights reserved. No part of this site may be reproduced without our written permission.