Moa were flightless birds endemic to New Zealand. There were nine species of varying sizes. The two largest species were the tallest birds on Earth – they reached about 3.6 m (12 ft) in height and weighed about 230 kg (510 lb) - while other some other species were smaller than a turkey. Moa were the only avian species in the world without any wings, and had large legs and no tail.
Females moa were much bigger than males; a very unusual reverse dimorphism. Most notable of this was the female giant moa, who were about 280% the weight and 150% the height of the largest males. This was recognised a scientific marvel and led to as many as 64 species of moa being declared at one stage.
As New Zealand had no native terrestrial mammals, moa were the dominant herbivores in New Zealand's forests, shrublands and subalpine areas for thousands of years, taking the role filled by the largest dominant herbivores (such as deer and elephants) in other lands. Until the arrival of the Māori they were hunted only by Haast's Eagle; the largest eagle ever known to exist with a wing span of ten feet and talons as big as tiger's claws. The extinction of the moa subsequently led to the demise of Haast’s Eagle, as moa was the eagle’s main food source.
Early Maori utilised moa for a variety of purposes: they fashioned fish hooks, harpoon heads, necklaces, pendants and other tools from the large leg bones, while the skins and feathers were used for clothing. Besides being eaten, the eggs were emptied and used as water containers. Moa extinction occurred around 1300 – 1440 (within 160 years of human arrival), primarily due to overhunting by Māori and habitat loss.