Emu or Ostrich: What Are The Differences?

Emu VS Ostrich, this is a showdown between two bird heavyweights. The common ostrich is the largest and heaviest bird in the world by a wide margin, and the emu comes in fifth, after the Somali ostrich and the northern and southern cassowary. These are two huge birds that are easy to compare. So what’s the difference between an emu and an ostrich?

Let’s start with an obvious similarity: neither the emu nor the ostrich can fly.

Although both birds are large, the ostrich is much taller at 9.2 feet (2.8 m) compared to 6.2 feet (1.9m), and the ostrich weighs 145 kg (320 lb) compared to the emu’s maximum weight of 65 kg (143 lb) . Both birds have long necks, lay huge eggs, and can acquire high speeds over long distances.

There are many other differences between emus and ostriches – read on to find out!

common ostrich (ostrich)

emu (new holland catfish)

Which is bigger, the ostrich or the emu?

Ostriches are indeed gigantic, not only among birds but among all animals.

common ostrich sizes

• On average, the common ostrich weighs between 63 and 145 kilograms (139 and 320 pounds)
• Male common ostriches range in height from 2.1 to 2.8 meters (6 ft 11 in to 9 ft 2 in). Female common ostriches range in length from 1.7 to 2.0 m (5 ft 7 in to 6 ft 7 in)

emu measurement

• On average, an emu weighs between 18 and 60 kilograms (40 and 132 pounds)
• The average height of a female emu is 1.56 meters (5 feet 1 inches) and that of a male is 1.48 meters (4 feet 8 inches).

As we have seen, an ostrich is about three times heavier than an emu and at least a quarter taller. Ostriches are stronger and more powerful, but emus are still large among birds. Their massive bodies and wings provide extra weight. Emus have relatively small wings.

The other major difference here is that female emus are taller and heavier than male emus – which is not common among birds. In contrast, male ostriches are larger and heavier than females—male ostriches weigh twice as much as females.

Male ostrich walking on the grass

Who’s faster: an emu or an ostrich?

Ostriches are able to reach faster speeds than emus. Ostriches are the fastest two-legged animals, easily reaching top speeds of 45 mph (70 km/h). Emus are also excellent runners, reaching speeds of up to 30 mph (50 km/h).

Both birds have tremendous stamina and can maintain high speeds for long periods of time. The ostrich is the best marathon runner on earth, it can run at about 35 mph for about 30 minutes to an hour, which enables it to run a human marathon of 26 miles in about 45 minutes.

Emus also have enough stamina to run non-stop for half an hour or more, cruising at 25 to 30 mph.

Both birds have exceptionally long, strong and special legs and large feet. Their legs are kind of elastic, enabling them to cover many meters in one step. For example, an ostrich can walk 5 meters in one step!

Emus are not as fast as ostriches, but they can still reach an impressive speed of 45 mph (70 km/h)

breeding and nesting

As mentioned earlier, it is unusual for female emus to be larger and heavier than males. Why? Because female emus are dominant and polyandrous, meaning they mate with more than one male.

Female emus typically mate with two to three males per year – the males incubate their eggs while the females wander around looking for another mate with whom to mate. Male emus can hatch and brood chicks from multiple fathers. Female emus compete with each other for unmated males, not the other way around, and can produce as many as three litters per year. Some emu mates stay together longer than the breeding season.

The researchers believe that reproductive advantage is why female emus are larger and heavier than males.

On the other hand, male ostriches are dominant and polygamous. Each male ostrich mates with a “harem” of 3 to 8 females. Males fight hard to maintain a harem. Male ostriches also incubate eggs and raise chicks. Ostriches chicks can merge into one large chick, so ostriches often end up raising the chicks of other ostriches. Emus are the same — offspring of multiple parents can merge into a large flock.

A male ostrich and three common ostriches

male and female

Female emus are larger than males. Both male and female emus also look very similar to males, although their plumage is slightly darker.

In contrast, Male ostriches are much larger than females. Male ostriches can be 3 feet taller than females and weigh 50 kg. Male ostriches also have dark black upper feathers and wings, while female ostriches are predominantly brown.

Ostriches are much more sexually dimorphic than emus, meaning male and female ostriches look different from each other.

female emu

life

Both birds are relatively long-lived. The average lifespan of an emu in the wild is about 20 years, but ostriches can live up to 50 years, and some can live up to 60 years.

Egg

Both birds lay exceptionally large eggs, but ostrich eggs are larger. An ostrich egg is about 6 inches long and weighs about 3 pounds, while an emu egg is about 5 inches long and weighs about 2 pounds – so not much difference.

Emu eggs are a distinctive dark green with blue spots, while ostriches lay off-white eggs. Both birds lay a lot of eggs, with ostriches laying 12 to 18 eggs and emus laying 5 to 25 eggs, a wide variation compared to other birds.

Ostrich egg

emu eggs

Behavior

Both emus and ostriches live in predominantly flat and arid climates. They cope with this environment in a similar way, as although both birds are flightless, they travel long distances in search of food and water. Both emus and ostriches can cover hundreds of miles in a week.

Emus are generally docile birds, except for females during breeding season. There are two documented cases of emus attacking humans. Ostriches, on the other hand, tend to be more aggressive and have been documented to viciously attack and even kill humans. An ostrich kicks hard enough to kill a lion. Both emus and ostriches have large, sharp claws.

ostrich eating grass

eating and foraging

Both ostriches and emus are omnivores, eating a variety of plants, animals and insects. Ostriches and emus are particularly fond of large insects such as large beetles, centipedes and spiders, but they will also eat small animals and reptiles.

Both emus and ostriches consume large amounts of stones and grit, which help them grind and digest food in their gizzards (specialized stomachs). Birds don’t have teeth — their gizzards help them chew their food. Since both emus and ostriches consume a lot of hay, their gizzards are very large.

Emu foraging on the grass

foot

Both emus and ostriches have large feet and sharp claws. However, ostriches only have two toes, while emus have three. Ostriches have very strange feet, and they’re surprisingly heavy considering their weight — a lot of weight and force is carried through just two toes!

emu feet

ostrich feet

Which is more common, an emu or an ostrich?

First of all it is worth pointing out that there is only one species of emu while there are two species of ostriches; the common ostrich and the Somali ostrich.

There is little data on how many wild ostriches there are in the wild, but one study puts it at 150,000.

Emus, on the other hand, number about 625,000 to 725,000 individuals, far more than ostriches. Ostriches are not commonly found in Africa, mainly because their habitat is very expensive. However, emus are common in some parts of Australia. In general, emus are more common than ostriches.

A small colony of emus in the wild in Australia

Are emus related to ostriches?

Emus and ostriches don’t appear to be genetically related, but they are from the same family of flightless birds called flat chest. Ratites include kiwis, cassowaries, ostriches, rheas and emus.

The study found that ratites don’t have much in common other than they can’t fly, although emus are loosely related to rheas and cassowaries. Scientists are puzzled as to why these flightless birds ended up in Australia, New Zealand, Africa and South America and whether they shared a common ancestor.

The previously accepted theory was that the common ancestor of the Ratites traveled across the supercontinent of Gondwana about 167 million years ago. Once the continents split up, these flightless birds moved away from each other and evolved independently.

A new theory suggests that the ratite is related to the Tinamous, a group of flying land birds that are distinct from the ratite. Interestingly, they think Tinamous learned how to fly at some point, while Ratites evolved flightless. Thus, each species of ratite, including emus and ostriches, likely evolved from a different species of Tianomous.

There is still much debate about the origin and evolution of flightless birds, especially the ostrich, which does not seem to be related to other flightless birds.

A large flock of ostriches, South Africa

Are there emus or ostriches in Australia?

Australia is the home of the emu. There are no ostriches in Australia and no emus in Africa. However, Australia is also home to the southern cassowary, another large flightless bird.

There are only two species of ostriches in Africa. Common ostrich and Somali ostrich. You won’t find ostriches anywhere else in the world except Africa.