The Elephant Birds, members of genera Aepyornis and Mullerornis, are a group of extinct birds that includes the largest bird ever to walk the Earth, Aepyornis maximus, sometimes simply known as the Elephant Bird. The Elephant Bird went extinct around 1649, not long after Europeans first arrived at the island where they lived, Madagascar, off the southeast coast of Africa. The largest bird that ever lived was entirely flightless and ate large fruits.
The Elephant Bird was the largest bird not only in size but in weight. It reached more than 3.3 m (10 ft) in height, with a weight approaching 454 kg (1,000 lb), or half a ton. Only the Giant Moa of New Zealand (also extinct) was taller, but it was much more lightly built. The Giant Moa was the second largest bird in the world at the time. The Elephant Bird had a more massive build, and would have been impervious to the medium-sized predatory mammals of the island. The only predators that the Elephant Bird would have needed to fear would have been the Nile Crocodile and humans, which would have raided its nest for its gigantic eggs.
The Elephant Bird lived alongside the natives of Madagascar for over a thousand years, from around 200 AD to its extinction. It was encountered by Indian and Arab traders visiting the island in the 7th, 8th, and 9th centuries, who supported their claims by bringing home eggs with a circumference of three feet.
The world's largest bird was also known to Kublai Khan, ruler of the Mongol Empire, who ordered the explorer Marco Polo to investigate reports of giant birds on the island of Madagascar. This occurred in the late 1200s, but Polo never located the birds. The Elephant Bird is thought to have been the inspiration for the gigantic bird called the "Roc" in the tales of Sindbad and Marco Polo, though the Elephant Bird was an herbivore, unlike the carnivorous Roc.
The Elephant Bird was a type of bird called a ratite, with a body plan similar to present-day cassowaries, emus, and ostriches. These birds are all flightless and lack a breast "keel" that provides an anchoring point for wing muscles. Due to a lack of predators on the island, the Elephant Bird probably didn't have the same running ability of other ratites, and would have been a sitting duck for predators like dogs once they were introduced by the Europeans. The Elephant Bird lived so recently that occasionally its unfossilized eggs are found, sometimes containing a semi-preserved embryo.