Emu vs Ostrich: Size, Speed, Eggs and Where They Live

Key differences at a glance

Emus and ostriches are both ratites, a group of large, mostly flightless birds with a flat breastbone that lacks the keel flying birds use to anchor their wing muscles. They look similar at a distance, with long necks, long bare legs and small wings, but they evolved on different continents and belong to different orders.

• The ostrich (Struthio camelus) is the largest living bird and the only member of its order alongside the Somali ostrich.
• The emu (Dromaius novaehollandiae) is Australia’s tallest bird and the closest relative of the cassowaries.

The table above sums up the main contrasts. The sections below explain each one. For the full story of each bird, see our emu and ostrich profiles.

Which is bigger, an emu or an ostrich?

The ostrich wins easily. Male common ostriches stand 2.1–2.75 m (6 ft 11 in–9 ft) tall and usually weigh 100–130 kg (220–290 lb); females are smaller, at 1.75–1.9 m (5 ft 9 in–6 ft 3 in) and 90–120 kg (200–260 lb). The emu stands 1.5–1.9 m (4 ft 11 in–6 ft 3 in) and weighs 18–60 kg (40–132 lb), so a big ostrich can weigh two to four times as much as a large emu.

The two birds also differ in which sex is larger. Male ostriches are bigger than females, while in emus the females are usually slightly larger and heavier. The emu is the world’s tallest bird after the two ostrich species; see our list of the largest birds in the world.

Feet, feathers and looks

Toes. An ostrich foot has just two toes, a large inner toe with a hoof-like nail and a smaller outer toe without one. This reduced foot is thought to help with fast running. An emu has three forward-facing toes, each with a sharp claw.

Plumage. Adult male ostriches are black with white wing and tail plumes, and females are gray-brown. Emus of both sexes look alike, with shaggy gray-brown feathers that hang loosely. Each emu feather has two shafts from one base, a feature found in emus and cassowaries.

Head and neck. The ostrich’s neck and thighs are mostly bare, with skin that ranges from pink to bluish gray depending on the subspecies. The emu’s head and neck are thinly feathered, with bluish skin showing through.

Wings. Ostrich wings are large for a flightless bird, spanning about 2 m (6 ft 7 in), and are used for display, shading chicks and steering at speed. Emu wings are tiny, about 20 cm (8 in) long, and almost hidden in the plumage.

Which is faster?

The ostrich is the fastest bird on land and the fastest animal on two legs. It can sprint at about 70 km/h (43 mph) and keep up around 50 km/h (31 mph) for long stretches, with strides of 3–5 m (10–16 ft). The emu reaches about 48 km/h (30 mph), with strides of up to about 2.75 m (9 ft).

Both are endurance travelers. Emus are nomads that may walk hundreds of kilometers following rain and food, and ostriches roam widely across open savanna and semi-desert.

Eggs and parenting

Eggs. The ostrich lays the largest egg of any living bird, about 15 cm (5.9 in) long and 1.4 kg (3.1 lb), with a glossy cream shell. Learn more in How big is an ostrich egg?. Emu eggs are smaller, about 13 cm (5.1 in) long and 450–650 g (1–1.4 lb), and famously dark green when fresh; see Why are emu eggs green?.

Nests. Ostriches use a communal nest: a dominant female and several other hens lay in one scrape dug by the male, which may end up holding around 20 eggs. An emu female lays about 5–15 eggs in a ground nest built by the male, though a male may also receive eggs from other females.

Who incubates. This is one of the biggest differences. Ostrich parents share the work: females sit by day, when their drab feathers match the sand, and the black male sits by night. Incubation lasts about 35–45 days. In emus, the male does everything. He sits for about 56 days with almost no food or water and then raises the chicks alone, as explained in Do male emus sit on the eggs?.

Where do emus and ostriches live?

Ostrich. The common ostrich is native to Africa, living in savannas, the Sahel and, in the southwest, semi-desert and desert. It once ranged more widely across North Africa and into the Middle East, where the Arabian ostrich was hunted to extinction by the mid-20th century. The Somali ostrich lives in the Horn of Africa.

Emu. The emu lives only in Australia, across most of the mainland. It prefers savanna woodland and open forest and is scarce in rainforest and the driest deserts.

Escaped farm ostriches have formed small feral groups in Australia, but in the wild the two birds have never naturally shared a home. Both are farmed outside their native ranges, including in North America and Europe.

Social life, lifespan and conservation

Ostriches often live in groups, from small bands to nomadic flocks of dozens of birds, sometimes mixing with zebras and antelopes. Emus are more solitary, living alone or in pairs and gathering in big flocks mainly when food or water draws them together.

Ostriches are long-lived. Captive birds commonly reach about 50 years, and one is recorded at over 62 years. Emus live much shorter lives: typically 5–10 years in the wild and 15–20 years in captivity.

Both species are listed as Least Concern by the IUCN, although the ostrich has vanished from parts of its former range and the emu’s island relatives on Tasmania, King Island and Kangaroo Island are extinct.

Which is more dangerous?

The ostrich is usually considered the more dangerous of the two. It is much heavier, and its forward kick, backed by the thick nail on its larger toe, can cause serious injury. Defending themselves or their chicks, ostriches are capable of killing large predators, and attacks on people, though uncommon, can be severe. Emus are generally shy, and documented attacks on people are very rare.

With either bird, the advice is the same: keep a respectful distance, never feed or corner them, and stay away from nesting birds and chicks. If someone is badly hurt, seek emergency medical help immediately: call 911 (US), 112 (EU) or 999 (UK).

Can emus and ostriches interbreed?

No. Although both are ratites, emus and ostriches are only distant relatives that belong to different orders and separated many millions of years ago. There are no known hybrids, and the two species do not meet in the wild.