Is A Penguin A Mammal? Here's Why Penguins Are Flightless Birds

Deepthi Reddy
Feb 29, 2024 By Deepthi Reddy
Originally Published on Nov 06, 2021
Fact-checked by Pradhanya Rao
Is a penguin a mammal? Let's find out.
Age: 3-18
Read time: 7.6 Min

Penguins are an enthralling bird species with their black and white feather coat and are sure to turn any head around.

Penguins belong to the order Sphenisciformes and the family Spheniscidae. Penguins cover 17-19 species under them and predominantly inhabit the southern hemisphere.

Penguins as a bird species have short feathers, and one can almost mistake penguin feathers for a thick fur coat. Baby penguins, also referred to as chicks, have woolly feathers, which keeps them well insulated in the extreme weather conditions they are brought into.

The unique plumage of penguins in white and black shades is a brilliant camouflage mechanism for these birds. This distinct camouflaging is termed countershading. Imagine a penguin swimming and its black back facing upwards; you will understand that the black back helps these birds blend in with the ocean's darkness below when viewed from above. This way, these birds go undetected by their predators. When peering from the bottom of the ocean, their white belly parts blend in with the ocean above. Isn't that a deep and clever way nature protects these birds from animals that threaten their existence?

If you wish to go on an expedition to find some penguins, you may be wanting to go and look for them on all continents present in the southern hemisphere. Yes, you read that right. The penguin species is dispersed widely in the southern hemisphere, except the Galapagos penguin which resides in the Galapagos Islands just above the equator in the northern hemisphere. If you do a deep dive into the geographic distribution of this penguin species, you will trace these birds to South Africa, New Zealand, parts of Australia, and Chile and Argentina in South America. We now know for sure that these penguins dwell beyond the polar regions too.

If you enjoyed our fun facts collated in this article, please browse through our Kidadl website and discover even more exciting articles like know your food better: how is margarine made; cool, fun facts for all; and is Dawn dish soap safe for dogs? Fun fact-finding is abundant in our exclusive articles for you.

What would a penguin be classified as?

Penguins can't fly to save their lives. Does that make these animals mammals? No, this species of animals is not mammals just because they are land-based mostly. How would you classify this animal species? Let's learn now.

Penguins fall into the category of flightless water birds. You may wonder why they are classified in this manner. These penguins are classified in the animal kingdom in the class Aves. Aves is the category that classifies animals in the bird's class. These animals are known to have developed from the reptile class but do not reach the distinction of becoming a mammal. They are warm-blooded, have feathers, and have scales on their legs. These features make penguins fall into the category of birds amongst other animals in the animal kingdom.

Let's know a lot more about this penguin species. When we hear the word 'penguins', our mind races to the end of the globe and we picture these animals being from Antarctica. We are talking about the emperor penguin species. Emperor penguins are the most massive and tallest penguins that exist, followed by the king penguin. Emperor penguins have spines and spinal cords, which makes them vertebrates. The emperor penguin species lives in Antarctica. The male and female emperor penguin look quite similar in their appearance and size. These emperor penguins measure 39 in (100 cm) in length, and they weigh up to 99 lb (45 kg).

We can also learn about a more common species of penguin known as Pygoscelis papua, also commonly known as gentoo penguins. They come third in size, following king and emperor penguins. Penguins of this species live on subantarctic islands. These penguins can get as tall as 35 in (90 cm) and weigh 19 lb (8.5 kg). Did you know that gentoo penguins are the fastest swimming penguins in the penguin species? These penguins can swim at a speed of 22 mph (36 kph).

If you see a group of penguins around, what is the term that you will use to refer to such a gathering of penguins? We would call such a gathering a raft if we see these penguins enjoying themselves in the water. If we find these penguins on land in a group, we can call them a waddle. There are a few other terms corresponding to a group of penguins, namely, a huddle, a rookery, or a colony.

Is a bird a mammal?

Birds and mammals are different classifications in the animal kingdom. What makes them distinct from one another, we will discover ahead.

Birds are not mammals. Birds can be more closely compared to reptiles than to mammals. Although they are vertebrates and are warm-blooded, they have feathers which makes them an isolated class of animals. Toothless beaks, modified limbs into wings, and their egg-laying nature are major differentiators, too.

So what are the characteristics of a mammal? All mammals have the presence of fur or hair on their body. Mammals are born through live birth. Young ones of mammals are fed milk by the mammary gland of their mothers. The presence of the mammary gland is the most distinguishing factor of a mammal. This is how the name of the class is derived.

Read on to know why penguins cannot fly.

Why isn't a penguin a mammal?

We know and understand that penguins are birds. So what are the features that make penguins not mammals or amphibians? Let's find out now.

Penguins share a common feature with mammals. It is the presence of a four-chambered heart, just like a human. Does that feature, like a human, make a penguin a mammal? No, there are other features of penguins that clearly show that penguins are in the class of birds class rather than in the class of amphibians. Penguins reproduce by laying eggs which is unlike a mammal who gives birth to a live young one. It is also unlike amphibians that reproduce via external fertilization. We can clearly state here that these Arctic dwellers are neither amphibians nor mammals.

Penguins have wings, and their wings are modified forelimbs. A penguin has feathers instead of fur or hair. Penguin feathers are oily, an adaptation that helps them bear the brunt of the cold weather. Penguin feet are different from the legs of a human. The feet of a penguin are webbed and assist them in swimming. It is interesting to learn that penguins can regulate the blood that reaches their feet to conserve the heat loss from their body.

Did you know the tail of a penguin produces an oil that is waterproof and gives the penguin an additional heat cover? One may observe a penguin always picking on its tail and then pecking its feathers. By this process, penguins distribute the waterproof oil across their body and keep an insulation layer on their body to escape the extreme cold weather.

Penguins are also known to be great distance walkers. Their feet support long-distance walks and penguins walk long distances during the breeding season. The breeding season may take these penguins as far as 60 mi (97 km). The feet of penguins function like a rudder during a swim. Their streamlined body also helps them swim at a good pace.

Are penguins warm-blooded?

Various animals have different adaptations in their body to regulate their body temperature. Do we know if a penguin is warm-blooded or not? Let's discover more.

Penguins are warm-blooded in the sense that their body maintains a persistent temperature irrespective of the weather outside. If you compare this feature with a cold-blooded animal, you will see that the body temperature of a cold-blooded animal will differ in varying weather conditions. Being a warm-blooded animal supports the life of a penguin to adapt itself very easily to the acute weather conditions it lives in. The other challenge they face in the sea may be in the form of predators like whales and leopard seals. On land, they are predator-free.

Did you know that penguins share their incubation duties? One partner fetches food from the sea, and the other incubates the egg. Now there is some life lesson on sharing responsibilities with a partner. Penguins are known to live and survive the harshest of frigid climates only due to their warm-blooded body. Penguins' bodies are also covered by a thick, fat layer that provides natural insulation from cold. Another interesting feature is the notable penguin huddle or their gathering in groups which helps them keep warm. The dark side of their body also helps in trapping the sunlight and retaining the warmth in their bodies.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for 'Is a penguin a mammal? Here's why a penguin is a flightless bird' then why not take a look at 'have you ever wondered how is leather made? Cool facts for kids', or king penguin facts?

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Written by Deepthi Reddy

Master of Business Administration

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Deepthi ReddyMaster of Business Administration

With an MBA under her belt, Deepthi has discovered her true calling in content writing. Her writing repertoire is diverse, covering travel, movies, pet care, parenting, animals and birds, and more. Her joy of learning and creating has helped her craft well-written and engaging articles. When she isn't writing, Deepthi enjoys exploring new cultures, trying different foods, and spending quality time with her two children aged 7 and 12.

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