Elephant birds and emus are two types of large, flightless birds that inhabited different parts of the world. Elephant birds lived in Madagascar, while emus are native to Australia. Despite some superficial similarities, elephant birds and emus belong to completely different taxonomic families and are not closely related.
Quick Facts
Elephant Birds
- Lived in Madagascar
- Went extinct around 1,000 years ago
- Could grow over 10 feet tall and weigh over 1,000 pounds
- Laid enormous eggs up to 13 inches long
- Part of the Aepyornithidae family
Emus
- Live in Australia
- Still exist today
- Grow up to 6 feet tall and weigh around 100 pounds
- Lay large green eggs
- Part of the Dromaiidae family
Taxonomy
Elephant birds belong to the extinct family Aepyornithidae, which was endemic to Madagascar. They are most closely related to the kiwi bird from New Zealand. Emus belong to the family Dromaiidae, which includes the emu as the sole living member. Emus are classified in the ratite group of flightless birds, along with ostriches, rheas, cassowaries, and kiwis.
So while elephant birds and emus occupied similar ecological niches as giant flightless birds, they belong to completely different taxonomic families and lines of evolutionary descent. Elephant birds are not a type of emu, nor are they closely related. The similarities between them are an example of convergent evolution – when unrelated species evolve similar adaptations for their environment independently.
Physical Features
Elephant birds dwarfed the emu in size. The largest elephant bird species, such as the giant elephant bird (A. maximus), stood over 10 feet tall and weighed over 1,000 pounds. Emus reach up to 6 feet tall and weigh around 100 pounds.
| Feature | Elephant Bird | Emu |
|---|---|---|
| Height | Up to 10 ft | Up to 6 ft |
| Weight | Up to 1,000 lb | Around 100 lb |
In addition to the size difference, elephant birds had much thicker legs and toes than emus. Their skulls and beaks were also larger and more robust. Emus have feathers over their bodies, while elephant birds had hair-like plumage that was more like mammal fur.
Despite the differences, both elephant birds and emus evolved as large, flightless birds with small wings. They both had long necks, small heads, and sturdy legs suited for running. These features represent adaptations for a cursorial, terrestrial lifestyle on the open landscapes where they lived.
Eggs
One of the most striking features of elephant birds were their enormous eggs. The largest elephant bird eggs could reach over 13 inches long and had a circumference of over 3 feet. They are the largest eggs known from the animal kingdom, weighing over 22 pounds.
In comparison, emu eggs are large but not nearly as gigantic as elephant bird eggs. Emu eggs are dark green and average 6 inches long by 5 inches wide. They weigh around 1.5 pounds. While larger than a chicken egg, they are dwarfed by the colossal size of elephant bird eggs.
The massive elephant bird egg likely developed to help the chick survive the long incubation period. A larger egg could hold more nutrients to sustain the developing chick. However, the giant size may have also contributed to their extinction, as larger eggs require greater resources to produce.
Where They Lived
Elephant birds lived only on the island of Madagascar off the southeast coast of Africa. Madagascar broke off from mainland Africa over 160 million years ago, allowing unique species like the elephant bird to evolve in isolation.
Emus are endemic to Australia, where they are found across most of the continent in a wide range of open habitats. During the Pleistocene era, emus also lived in Tasmania, but died out there sometime after European settlement.
So while they occupied similar ecological niches, elephant birds and emus lived on landmasses separated by over 5,000 miles of open ocean. This geographic isolation means they represent completely independent evolutionary lineages.
When They Lived
All known elephant bird species went extinct around 1,000 years ago, shortly after human colonization of Madagascar. Some reports and archaeological finds suggest that a small dwarf species may have persisted until as recently as 500 years ago before also dying out.
In contrast, emus continue to exist today across most of Australia. Along with the ostrich, emu, and rhea, they are one of the few living ratites able to survive into the modern era. However, some isolated emu populations on offshore Australian islands did go extinct after European settlement of Australia in the late 1700s.
So while elephant birds represent an extinct lineage, emus persist today as remnants of the once more diverse ratites that lived across the southern continents. Elephant birds went the way of the moa, dodo, and other extinct island birds, while continental emus avoided that fate.
Behaviour
Little is known about the natural behavior of elephant birds, since they died out centuries before modern scientific study. Like other ratites, they were likely swift runners that could deliver powerful kicks to predators with their thick legs. Their diet probably consisted of fruits, seeds, small animals, and foliage.
Emus are well-studied today. They are fleet runners who can sprint up to 30 mph. Their diet consists of seeds, fruits, insects, and green vegetation. Emus exhibit a winter breeding season from April to June in their native Australia. The male incubates the eggs and raises the chicks.
Both elephant birds and emus would have occupied important roles as large herbivores in their ecosystems. Scattered reports suggest elephant birds impacted vegetation structure on Madagascar. Emus continue to shape the ecology of Australian grasslands and open woodlands today.
Relation to Humans
Elephant birds appear to have been driven to extinction by human activity on Madagascar. Hunting and habitat loss from human settlement are probable causes. Elephant bird egg shells were used as containers by early Malagasy peoples.
Emus remain a common sight across Australia today. Aboriginal Australians hunted emus for meat, feathers, oil, and eggs. The large flightless birds are easily rounded up, making them a plentiful food source for indigenous peoples. European colonists continued hunting them for meat and feathers.
However, the emu holds a more prominent place in modern Australian culture. The large bird is featured on the country’s coat of arms. Emu farming today provides meat, oil, and leather. And emus themselves are Australian icons, appearing in art, stories, advertisements, and zoo exhibits worldwide.
Conclusion
While elephant birds and emus have some superficial resemblances as giant flightless birds, they do not share a close evolutionary relationship. Elephant birds were part of the extinct Aepyornithidae family endemic to Madagascar. Emus belong to the Dromaiidae family of ratites originating in Australia.
Elephant birds were much larger but went extinct around 1,000 years ago, probably due to human activity. Emus survived into modern times and remain a common Australian bird today. So while they occupied similar ecological roles, elephant birds represent an extinct lineage while emus persist as icons of Australia’s unique wildlife.
