Why Don’t Ostriches Fly

Can Ostriches Fly: How Did Ostriches Evolve But Remained Flightless?

The flightless ostrich is an African native and is one of the largest birds in the world. So, if you are a person who is interested in animal curiosities, then you probably wondered why you’ve never seen an ostrich fly even though it has wings. From a scientific point of view, it is fascinating to understand how evolution shaped their wings.

Their massive body is one of the reasons, but that is not all. In this article, you will learn everything about these large flightless animals, including information regarding their habitat, eating habits, and more. So, let’s begin!

How Did Ostriches Evolve But Remained Flightless?

The first thing you should know is that ostriches are among several creatures of the ratite bird family. This family includes species such as rheas, kiwis, cassowaries, and emus. This bird group mostly contains flightless feathered species.

Starting Point – Darwin’s Theory

The first thing you should understand is that ostriches’ bodies are directly linked to the mass destruction of the dinosaur population. So, when dinosaurs ruled the world, they took up most of the land surface, making it their living environment. But with their extinction, they left a lot of free space to be repopulated.

Many aerial animals, primarily birds, started adjusting their bodies to terrestrial life. One of these birds was the ostrich. As time passed and evolution followed its natural path, these birds gained weight and started to modify their bodies based on the new conditions.

Naturally, as they grew to the size they are now, they lost the capacity to fly.

Why Don’t Ostriches Fly? Anatomical Facts

Ostriches cannot fly due to some anatomical differences when compared to the other birds. Simply put, ostriches lack a very fundamental part of the sternum – the breastbone. The reason why it’s so important is that this “keel” body part connects to the solid pectoral muscles, which are directly responsible for flying abilities.

Scientists do not precisely know why ostriches developed to be flightless. They are considered to be in the same category as other large animals – they had giant ancestors and no natural predators to hunt them down.

It is believed that ostriches are directly related to a huge creature called the elephant bird, which lived right after the dinosaurs’ extinction but before the evolution of mammals. So there they were, with no potential predators to turn them into prey. In time, they developed large bodies and small wings, turning them into the flightless birds we know today.

Now, you may wonder why they didn’t evolve back into flying birds when predators started to appear. Well, they did evolve, but differently. Ostriches run, and they are very fast. They use their powerful leg muscles to compensate for their inability to fly.

The reason they evolved in this way lies in their regulatory DNA. This part of their DNA is responsible for when and where genes have been “turned off”. Researchers state that evolutionary changes happen due to various mutations in protein-making genes (1).

Did Ostriches Ever Fly?

No, technically, they did not. The ostriches we know have always been flightless birds, as researchers have discovered so far. Nevertheless, based on evolutionary science (2) and the concept of regulatory DNA, ostriches might have some ancestors that flew.

Scientists discovered a flightless ancestor of ostriches and other related species in the Cretaceous period. When the supercontinent broke up, animals moved to different continents. The end result was the evolution of different flightless bird populations today, such as emus, kiwis, ostriches, and so on.

However, discoveries continue to bring new facts to light. DNA extracted from the remains of the elephant bird found in Madagascar links them to ostriches. But their closest relative turned out to be the small and fragile kiwi bird rather than ostriches themselves.

The DNA Story Of Ostriches

As you can imagine, some scientists still have questions regarding ostriches’ flying inability. Therefore, they continue to analyze their DNA pattern.

The primary speculation was that their ancestors lost the ability to fly. But we now that this theory is wrong since we have clear proof of the ostrich’s direct connection to elephant birds.

Instead, it is more likely that the regulatory DNA turned off the flight ability of these birds.

Let’s take the “use it or lose it” theory to simplify things. Ostriches, kiwis, emus, and many other flightless birds “forgot” how to fly because they no longer needed to, and they therefore lost this ability. Just like an atrophied muscle, their wings shrank in size over time.

Fascinating Facts About Ostriches

Ostriches can swim

Although swimming is quite unusual for these birds, ostriches indeed swim even though they can’t fly. They keep themselves floating on the water surface and use their long legs to move through the water.

Ostriches can “glide”

Ostriches do not fly. However, these flightless birds have outstanding running skills.

When they reach a speed of 50 miles per hour, ostriches look like they are flying. However, they cannot take off into the air. Ostriches have a long and elegant stride that helps them run fast to any distance. Once an ostrich gets up to speed, its wings will flap, and the ostrich may appear to glide through the air.


Ostriches are primarily herbivorous; however, they sometimes eat insects or small lizards.


Although they do not use their wings for flying, ostriches rely on these body parts for keeping their balance when running. Furthermore, they will also use their wings for courtship displays during the mating period.


Ostriches have multiple stomachs which they separately use to secrete gastric juices and for mechanical function, helping to process the food they ingest.

Renal System

Unlike many other birds, ostriches secrete urine separately from feces.


Ostriches do not have many natural enemies considering their massive and powerful bodies. The only two predators are cheetahs and lions. Their tactic is sneaking up on the adult birds and attacking them. Luckily, ostriches have long and powerful legs to outrun their enemies. Not only can they reach 50 miles per hour, but they can also keep up a steady rate of 31 miles per hour for long distances.

Some may add a third enemy to the list of predators, but this one only attacks their eggs – the Egyptian vulture.


The plumage is soft and fluffy and can protect them from cold nights and harsh winters. Unlike many other birds, ostriches lack the glands that make their feathers waterproof.

Defense mechanism

An interesting evolutionary aspect is ostrich claws. The flightless birds have developed claws at the end of their toes to protect themselves from possible predators.

Over time, ostriches have developed an entire defense system to protect themselves from possible enemies. For instance, males have dark feathers for camouflage during the night.

On the other hand, females have a lighter brown plumage that blends perfectly with the daytime environment. So male will incubate the eggs at night, while females will take on this responsibility during the day.


Ostriches lay the biggest eggs of all egg-laying species. An ostrich egg is the equivalent of two dozen chicken eggs. A female ostrich will lay around 15 eggs per month.

Last Thoughts

Ostriches cannot fly, and plenty of scientific reasons explain this fact. These massive, flightless birds use their wings only for display purposes, to shade chicks, maintain their body temperature, and for balance and direction change while running.

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