Because they are birds, one would ordinarily expect that emus can fly. But then, when you realize that they are the second-largest bird alive, next to the ostrich, you may have second thoughts.
Can emus fly?
Emus cannot fly. Like other birds in the ratite group, emus are flightless.
Their flightlessness stems from specific differences in their anatomy relative to the anatomy of birds that can fly. While their wings are not big enough to support their massive weight, the primary reason emus cannot fly is a bit more complex.
Not to worry, we discuss some reasons emus cannot fly in this article. We also talk about why they still have wings, how the ability to fly changed as they evolved, and much more.
Can Emus Fly?
Emus cannot fly. Like other living ratites, emus are not anatomically primed for flight. But while they cannot fly, emus can run, walk, and swim just like other birds.
The inability of emus to fly comes from a combination of anatomical factors. They include wing size, body size, and the absence of a keel.
Wing Size/Structure and Body Size
Relative to their large-sized bodies, emus have tiny wings – about 7 inches long.
On average, emus are 5.7 feet tall, and they weigh 79 to 88 pounds. With such body size, their wings cannot lift them in flight.
Besides being quite undersized, the wings of emus are not well-structured.
For birds to fly, they need strong, well-built wings that can push enough air to propel their body upwards.
In addition, the feathers on the wings of an emu are not structured to promote flight. Emu wing feathers are more like fur.
Absence of a Keel
Birds like emus, ostriches, and kiwis have no keel or pointed breastbone; their breastbones are flat. Hence, their flightlessness.
The keel is a ridged part of the breastbone of most birds. It functions as an anchor for the pectoral muscles, which are required for flight. But since emus have no keel, they cannot fly.
Did They Ever Fly?
Some studies have hinted that earlier emus could fly. But as those earlier birds evolved, they lost the ability to fly.
Some experts state that the flightlessness in emus may have been caused by mutations in regulatory DNA.
Some other experts believe that emu ancestors lost their ability to fly as they became lazy. This laziness is possibly an upshot of having fewer predators after dinosaurs went extinct.
The dinosaurs were thought to be the primary threat to emus. And once they were gone, emus did not really have to fly, so they stopped flying. Then over time, their ability to fly became weaker until they became flightless.
Of course, since the primary threats were gone, they survived without flight.
Besides the absence of threats, emus survived thanks to their rapid legs. Emus can run as fast as 30 mph, so they can escape many predators without flight.
Why Do They Have Wings if They Can’t Fly?
While the wings of emus are largely vestigial, they still perform some functions.
For one, the wings of an emu can help in cooling the emu. When hot, emus stretch their wings out to allow air circulation around their body.
Besides helping with cooling, emus use their wings to steer themselves while running. The wings also help with balance while running.
Emus may also use their wings for courtship displays.
Do Their Wings Help Them Run Faster?
The wings of emus do not necessarily help them run faster. Instead, the wings help them maintain balance while they run.
The balance offered by their wings makes it possible for them to run for long distances. It also makes it possible for them to change direction without falling.
Emus are the only bird with calf muscles. This fact may be one of the reasons they are pretty fast.
Calf muscles are crucial in propelling the body forward with every step. And as they become stronger, one can become faster. So, perhaps the strength of their calf muscles is one reason why emus run pretty fast.
Another reason emus run pretty fast is their stride. Thanks to their long legs, emus have a stride as long as 9 feet when running. In other words, for each step an emu takes while running, it covers a distance longer than the height of an average human.
Most of an emu’s leg muscles are located at a high position on the hip and the thigh bone. Contrarily, the swinging parts of the leg are in lower spots. This arrangement makes it possible for emus to take more frequent steps while running. And this contributes to their elevated speed.
19 Other Flightless Birds
Besides emus, the following birds cannot fly:
- Common Ostriches
- Somali Ostriches
- Fuegian Steamer Ducks
- Chubut Steamer Ducks
- Falkland Steamer Ducks
- Kakapos (Owl Parrots)
- Broadbreasted Turkeys
- Campbell Teals
- Titicaca Grebes
- Guam Rails
- Flightless Cormorants
- Tasmanian Nativehens
- Inaccessible Island Rails
Emus in existence today are flightless. It is believed that ancestral emus may have been capable of flight. But the ability to fly gradually faded from them over time, leaving modern emus flightless.
While emus do not fly, they use their wings to steer and find balance while running. The wings also help in cooling their bodies.