Can Birds Swim?

Birds are known primarily for their ability to fly.

And yet, flying does not characterize any animal as a bird.

That said, certain birds have adapted to an aquatic lifestyle rather than an aerial one.

Which means

Aquatic birds like ducks and penguins can swim in the water.  

Still, the idea of identifying a bird without the ability to fly comes as a shock. 

So, you may be wondering:

Can Normal Birds Swim?

They most certainly can.

Now, scientists characterize birds based on the distinct shape of their skeletons, presence of feathers, toothless beaks as well as hard-shelled eggs.

Flying is not a mandatory character to be considered as a bird.

In fact, flying appeared late during evolution when bird ancestors were trying to better adapt to their ecosystems. 

No doubt, soaring on winds dramatically improved survival odds for several birds. 

However, flying is not practical for all birds.

For instance, animals living in freezing cold regions like the north or the south pole acquire their staple diet through oceans.

And so, for such animals, the ability to swim seems far more suitable than the ability to fly. 

You see,

While most birds became adept fliers, others developed into expert runners and divers. 

Even so, we assume that all birds are supposed to fly.

So much so, that if a bird doesn’t fly, we consider it lacking somehow. 

How so?

Well, we normally mention “ostriches are flightless” before we move on to describe them as “the largest and fastest birds alive”.

That said if flying was the only parameter to define an animal as a bird.

Then, bats would be considered birds, not mammals. 

Also, those flying cockroaches would be your regular domestic bird pets. 

Just saying.

Anyways,

Though not all birds can swim, those that do are certainly normal. 

Can Flying Birds Swim? 

Some can, but it varies among bird species.

You see, like other animals, birds also faced the same evolutionary dilemma between becoming either generalists or specialists.

In simple words, 

A bird can be an average runner, flier, and swimmer at the same time.

However, a bird may have to give up on one lifestyle to become a master of another.  

For instance, ostriches can run as much as 96km per hour, but they can neither fly, nor swim.

Related article about ostriches – Are ostriches dangerous? 

Similarly, vultures renounced swimming and proficient running to be able to fly as high as 37,000 feet above the ground. 

Related article – Why do vultures spread their wings?

Likewise, penguins gave up on flying and running to maintain a skilled aquatic lifestyle, diving as deep as 1800 feet below water. 

Related article – Can penguins fly?

In contrast, Puffins can fly, run, and even swim.

However, they are neither great fliers, nor expert swimmers.

Also, their walking capacity is limited.

So, 

Not all flying birds can swim, but those that do cannot swim as expertly as flightless aquatic birds.

“But how do birds decide whether to become masters of one or jack of all trades?”

The choice of becoming an expert swimmer or adequate flier depends mostly on a bird’s surroundings, habits, and also their predators. 

For instance, penguins don’t have many land predators, and their primary food source comes from the deep oceans. 

Penguins don’t really need running or flying abilities as much as they need diving.  

That said, certain birds can swim as much as they can fly. 

Which Birds Can Swim And Fly?

These include:

1. Terns
2. Pelicans
3. Petrels
4. Ducks
5. Gannets
6. Boobies 
7. Puffins
8. Loons
9. Grebes
10. Cormorants

Some of these, like arctic terns, can fly thousands of miles each year for migration and still be able to float on water. 

Still, swimming and flying represent two different sets of adaptations. 

For instance, to become airborne a bird needs to be lightweight.

Therefore, flighted birds have developed long but hollow bones.

In contrast, swimming birds need to be heavyweight to fight off water buoyancy. 

Figure 1: Comparison of Adaptations Required for Flying and Swimming in Birds

A comparison of these flying and swimming adaptations (See figure 1), leads to a more intriguing question:

How Do Flying Birds Manage To Swim?

Seemingly, they make certain compromises in their flying and swimming abilities. 

For instance, puffins can swim as deep as 200 feet below water.

However, they can hold their breath for merely 20-30 seconds.

And so, 

Puffins swim down to grab their prey and come back up to catch their breath.

Truly, a breathtaking sort of hunting.

Anyways,

Now, Puffins can swim by flapping their wings vigorously, reaching as much as 400 beats a minute.

They also fly almost the same weight.

But their bodies are rather compact with short feathers to ease swimming.

So, 

A typical puffin weighs about 0.5kgs with a wingspan of 24 inches.

Meanwhile, a hawk of the same mass can have a wingspan up to 1m wide.

Therefore,

While a puffin can reach only as much as 77km per hour midair, a hawk can exceed 120 km per hour.

Still, flying costs puffins a great deal of energy. 

And so, they don’t fly much further from the shore.

The compromise between swimming and flying adaptations also decides how expert a bird is at swimming or flying.

This is best manifested among Ducks. 

You see, all ducks can fly, walk, and swim.

However, based on their adaptive skills, they are divided into two groups: 

1. Dabbler Ducks
2. Diver Ducks

While dabbler ducks tend to be swift fliers, they cannot swim deep waters.

Meanwhile, diver ducks can dive with ease, they find flying rather difficult (See table 1)

	Dabbler Ducks	Diver Ducks
Defining Characteristic	These ducks ride on shallow or surface water layers.	These ducks dive relatively deep waters, up to 40 feet.
Dietary  Habits	Skim the water surface for food, often tip their heads underwater while feeding bottoms up.	Dive in water to catch prey, move through waddling fast feet.
Prominent  Features	Webbed but body-centered feet to ease walking. Broad wings for smooth flying. Take off like rockets and easily land. Elongated necks to help capture prey. Less breathing capacity.	Feet farther back in the body to make bodies more streamlined for swimming. Small wings, but compact bodies. Run before taking to flight, must skid in water to land. Average neck size. Able to store about 70% more oxygen per kg than dabblers.
Examples	Mallards, Widgeons, Teals, Pintails, Shovelers, Gadwalls, Wood Ducks.	Redheads, Canvasbacks, Scaups, Goldeneyes, Ringnecks, Mergansers, Buffleheads.

Table 1: Comparison of Dabbler and Diver Ducks with respect to their Swimming and Flying Adaptations

While these comparisons help in understanding how a bird gets to achieve both swimming and flying at the same time.

However, it does not explain:

How Do Birds Swim?

Now, for any animal to swim, it needs to be able to steer through water. 

Aquatic birds achieve this by employing these mechanisms:

1. Wing Flapping
2. Feet Propelling
3. Combination of both Feet and Wing movements

The exact mechanism depends on a bird’s anatomy as well as how deep a bird needs to swim.

But, there is no precise way to classify aquatic birds based on these adaptations. 

So, I present to you a humble attempt at dividing these birds based on their swimming adaptations.

1. Deep Sea Divers

If a bird is to swim deep within the ocean, it must commit to this kind of lifestyle. Thereby giving up on flying as well as walking.

The best examples of such birds are Penguins and Great Auks.

Here are a few of the major adaptations of these birds. 

Deep Water Troubles	Solution	Adaptations
Inability to Breathe	They can hold breathe for up to 23 minutes.	Reduce Body metabolism. Reduce heart rate to 5 beats per minute. More Lung Capacity. Greater blood volume. Better blood buffering to avoid Carbon dioxide forcing the bird to breathe.
Water Pressure	Sturdy Body Built	Thick bones within the body. Subcutaneous fat layer or Blubber. Tightly packed muscles.
Propelling Mechanism	Short but strong Wings	Joints in arms and legs are fused to avoid snapping. Wings can move both forwards and backward with extreme power.
Reduce Buoyancy	Compact Streamlined bodies	Torpedo Shaped Stature. Webbed feet are located at the far end of the body, acting as rudders. May eat pebbles to gain temporary weight.
Cold Water	Active Thermoregulation	Reduce Body Temperatures to maintain homeostasis. Small waxy feathers trap warm air on the entire body. Countercurrent heating ability, thereby transferring heat to peripheral veins and arteries.
Reduced leg Function	Move by sliding on bellies.	Live in freezing cold areas with not many land predators. So, don’t need to walk as much.

 

2. Dive-Plungers 

Since an average bird’s body is built rather buoyant.

Therefore, diving deep requires heavyweight or muscular builds.

And so, 

Most birds cannot reach more than a few meters depth within the water. 

But certain aquatic birds have developed an ability to dive through great heights directly into the water, thereby achieving a swimming depth otherwise impossible. 

Such birds include terns, gannets, and kingfishers.

These can dive from a 30-meter height above water while entering the water surface with a speed of about 100km per hour.

The dive impact itself is so great that a bird reaches 20-meter below water within a few seconds.

This kind of lifestyle requires certain adaptations.

Dive-Plunge Issues	Solution	Adaptations
Need altitude to dive in the water	Have the ability to fly.	Wingspans are short but strongly built such as to endure the diving impact.
Requires Precision  Otherwise, may collide and break their necks.	Have strong eyesight. Also, a well-built body.	They do not plunge dive unless they locate some prey. Usually follow dolphins to ensure their prey stays near the water surface.
Cannot use their wings for moving within the water.	Use leg and feet propellers.	Looks much like frog movement.
Wet Wings.	Preening	Preen glands are located on the rump of a bird, Needs extensive preening after every hunt.
Extreme Impact	Dive Headfirst.	The bones of legs are filled and massive, Skulls have more calcification than regular birds. Hold their wings close to the body, to avoid snapping.

3. Shallow-Water Swimmers

These birds don’t need to reach high altitudes to dive through water.

However, they cannot go beyond a certain level of water.

These include loons, cormorants, and mallards.

Shallow Water Swimming Troubles	Solution	Adaptations
Buoyancy	Compact bodies with less air storage capacity.	Need to breathe every few minutes. Muscles are strong enough to fight off water pressure. live in shallow waters.
Precision	May be unable to find prey within seconds.	Muscles able to chase off prey.
Propelling Mechanism	Either short wing, but mostly leg propellers.	Some species have a long bony process on their lower legs. These cnemial crests work as a lever for propelling the bird within the water. Feet astride to act like oars.

Interestingly, cormorants can be trained to hunt. This is common among Chinese fishermen that train these birds from the moment of their hatching.

4. Floating Aquatic Birds

These birds don’t go much beyond the water surface.

The best examples include dabbler ducks, grebes, and certain Loon species.

Floating Issues	Solution	Adaptations
Thermoregulation	Down Feathers and controllable blood flow.	Ruffled down feathers help birds trap warm air next to the skin. Vasoconstriction allows limited blood flow through the skin to keep bodies from experiencing freezing cold.
Wet Feathers	Have waxy water-proof feathers. Enlarged Uropygial or Preen gland.	Vane feathers have barbs that have extensions called barbules. The barbules have further hooked like extensions called barbicels that join overlapping vane feathers. Thereby, creating waterproof feathers. Additionally, ducks preen their bodies to keep them waxy.
Feeding with beaks is hard	Have flexible long necks.	Eat only in shallow waters
Floating Costs Energy	Passive Buoyancy	Have air trapped within their feathers. Also, have deep air pockets within the lungs. The feet are naturally webbed to ease floating.

 

Apart from all these, certain birds prefer living around water bodies and may not necessarily swim.

For instance,

1. Swans and flamingos tend to stay in shallow waters.
2. Eagles and storks hunt fish by diving above water. Their feathers can resist water spray.
3. Some birds like grebes can walk on water by moving their feathers and feet.

Now, you may be thinking, if there are:

Birds That Can’t Swim

Most birds lack swimming adaptability, so they are unable to swim through water.

These include flighted land birds:

1. Songbirds like parrots and crows.
2. Raptors like hawks, vultures, and owls.
3. Hummingbirds

Even babies of certain swimming birds cannot swim. 

But one cannot teach a non-swimming bird to swim. 

Though flightless birds can survive a few minutes in waters by struggling to stay above water level.

But they too cannot swim and are highly likely to drown.

These include:

1. Ostriches
2. Emus
3. Greater Rhea

However, kiwis can swim.

Wrapping Up

Certain birds can swim.

However, swimming requires certain adaptations including the ability to breathe, maintain body temperature, and steer through waters.

Which means, most birds are unable to swim in the water.