Though penguins have strong pectoral muscles to produce vigorous flapping.
However, they are quite heavy birds with short non-bendable but sturdy wings.
Which means, they cannot lift themselves up in the air and fly.
Penguins have adapted to swim underwater just as most birds fly in the air.
Still though, penguins don’t strike as heavy birds to most people.
So, you may be wondering:
Are Penguins Too Heavy To Fly?
They most certainly are.
For instance, birds have large wings and strong pectoral muscles to steer through winds.
Other flight features include a strong sense of direction as well as beaks and tails to maintain body balance.
However, the most admirable adjustment is a bird losing its weight.
For the same reason, birds have also shunned long intestines, bladder, body fat, large brains, and even much of liver.
However, penguins did not compromise on their body weight.
Penguins are among the heaviest of birds in proportion to their body size.
But the question is..
“What Makes Penguins So Heavy?”
Here are the main reasons:
1. Regular Bones And Muscles
Unlike flighted birds, penguin bones are as thick as any other mammalian bones.
This means they are also much heavier and stronger than other bird bones.
If you are up for imagining it then think about it like this
It’s like penguins have calcium rods as their skeletons while flighted birds have Swiss porous cheese as their body supports.
Furthermore, penguin muscles are far thicker and more developed than other birds.
Thereby, giving them more weight.
Flighted birds have minimum amounts of fat to lower their weight.
In contrast, penguins tend to live in freezing cold environments.
Therefore, they have a thick fat coat called “Blubber”, underneath their skins to provide them with insulation.
This adds weight to a penguin’s body but also lets it float in water.
3. Dense Bodies
Flighted birds have their weights distributed throughout their bodies, giving them less dense builds and the ability to float in thin air.
Penguins have compact bodies packing more weight in small sizes.
For instance, Yellow-eyed Penguins (Hoiho) are about 30-inches tall and weigh 8.5kg.
Meanwhile, a bald eagle of the same height can weigh only as much as 6.3 kgs while having at least a 2–3m wingspan.
That said, the weight alone does not explain why penguins don’t fly.
You see, Griffon Vultures can weigh about 11 kgs and can still reach 37,000feet above ground.
Now, an Emperor Penguin is about 1.2m tall and can weigh as much 45Kg.
So, surely it is too heavy to fly.
But what about smaller Penguins?
For instance, Macaroni Penguins are approximately 28-inches tall and weigh 5 kg.
So, in principle, they should be able to fly.
All currently known 17 species of penguins do not fly.
So, you must be wondering:
Why Can a Penguin Not Fly?
Because penguins evolved to become swimmers rather than flying birds.
You see, evolution comes with a compromise.
And so, penguins literally gave up on flight abilities to become adept swimmers.
Here is what penguins gained to become swimming masters:
1. Streamlined Bodies
Their plumage is oily and smooth.
Also, their feathers are quite stiff with the ability to trap air bubbles.
Penguins slide through water layers with minimum friction and water drag.
2. Bulky Bodies
As the water depth increases, so does the water pressure.
Therefore, only a sturdy thick body can survive underwater.
Otherwise, it may simply collapse.
- Non-porous, thick bones.
- Blubber- a fat coat underneath their skin.
- Concentrated body mass.
Therefore, even the smallest of penguins like the blue penguins can weigh 1.5 kgs with merely 33 cm height.
But heavy bodies enable penguins to dive deeper than 1,800 feet below sea level.
They can easily find fish, crustaceans, and squids in the most freezing of colds.
Unlike flying birds, penguins don’t have big feathers.
Also, the bones in the wings are fused together to form a flap rather than an elbow.
If a penguin had large wings, these would have just hindered its swimming ability.
You see, if these wings could bend, they would have broken under water pressure.
4. Webbed Feet
A penguin’s foot has 4 toes arranged in the same direction, but one toe is relatively smaller than others.
The space between these toes is webbed with a thick, flexible muscular sheet.
Penguin feet resemble scuba diving swim fins.
While penguins use their feet to navigate through water layers, they have extremely short legs.
Therefore, they walk a bit weirdly on the ground.
But penguins can walk a long distance by sliding on their bellies called “Tobogganing”. So, this adaptation does not change any penguin’s normal routine.
5. Holding Breath
Penguins cannot breathe underwater.
But their lungs can hold air for long periods.
So much so that
This also means that penguins will have to come above the surface every 20 minutes to breathe.
But all these adaptations imply that penguins used to fly once.
Did Penguins Ever Fly?
Even the oldest penguin fossils indicate an absence of flying ability.
However, close penguin relatives do have flying abilities.
However, these birds have large wingspans and can fly for miles.
While they can swim, they cannot take deep dives as penguins do.
Now, penguins do have the muscles to fly, but they don’t.
So, a more appropriate question would be asking:
Why Did Penguins Evolve Into Divers Instead of Flying Birds?
Because flying was not much use to penguins.
In such freezing cold, predators are hard to come by as food resources are scarce.
Most of the food comes from the Ocean.
There are no trees and penguins don’t migrate much.
So it makes more sense for penguins to dive into the water rather than fly
But as in all cases, true mastery comes at the cost of compromises.
Penguins lost the ability to fly to become masters in diving.
Birds that can both swim and fly cannot do both these activities as well.
For instance, Puffins are closer to penguin body build.
These birds can swim as well as fly.
However, they cannot fly far from shore and not dive as deep as penguins.
The same compromise is seen in other penguin relatives including petrels, cormorants, loons, shearwaters, and grebes.
To date, there is no direct evidence suggesting that Penguins could ever fly.
But the last time I argued that penguins cannot fly, someone showed me a BBC video titled “Miracles of Evolution” featuring flying penguins.
The video included graphic evidence of penguins flying thousands of miles from mainland Antarctica to the Rainforests of South America.
However, the video was posted on March 31st, 2008, to celebrate April Fools’ Day and, to promote BBC iPlayer.
The video was so well made that MSN included it as their twelve “Hoaxes of the Decade”.
BBC did release another video on how they fooled the world into believing penguins could fly.
That should relieve you of any suspicion.
Can Penguins Fly Underwater?
They kinda do.
This sounds like ornithologists are so fixated on making penguins fly.
However, a fish swimming in the ocean moves differently than a penguin does.
While penguin flaps resemble those of a seal however, these two species evolved separately from each other.
Besides, their strokes differ a great deal.
And so, ornithologists agree that:
Penguins diving underwater is analogous to birds flying in the air.
Now, water is about 900 times denser compared to the air.
Therefore, penguins need to move with more vigorous flapping than any flying bird.
Penguins have developed strong pectoral muscles.
You see, a typical bird has only strong chest muscles and less developed shoulder muscles.
It can actively flap its wings downwards and relies on the air itself to move its wings upwards.
Such powered strokes allow penguins to swim at 15-30 miles/hour.
Swimming is so essential and easy for penguins that they spend up to 75% of their lifetime beneath the water.
Penguins can also control their direction.
Typically, they tilt their head to a side, lower down one foot and raise their tails while flapping all the way.
Penguins cannot fly but they are great swimmers.
They have streamlined bodies, flapping capacity, as well as weight for diving.
This is mainly because penguins have thick bones.
They can actually fly but underwater
And they are really good at it too!