Incredible Facts

Why did the Moa grow so large?

Small species of moa were about the size of a turkey, but the largest could have reached more than 3m in height with its neck fully stretched, and would have weighed 250kg (more than six times the weight of an average child). Moa are unique because they are the only bird known to have had absolutely no wings.

The moa was able to grow so large because there were few large predators in New Zealand. Large herbivores (plant eaters) find it harder to escape or hide from predators, but on islands such as New Zealand there are generally few or no large predators, so small plant eaters, such as birds, can grow very large.

However, the moa did have one predator to contend with - the world’s largest eagle, Haast’s eagle (Harpagornis moorei). This giant bird of prey had a wingspan of up to 3m, and it loved to eat the moa.

Along with the moa, this magnificent eagle is extinct. Humans were responsible for the extinction of the moa. They introduced predators which preyed on the moa and ate its eggs; they cut and burned the forests which were the natural habitat of the moa; they hunted it for food - skin and feathers were used for clothing; bones were used to make fish hooks, harpoon heads and jewelry; eggs were eaten, and the shells used as water containers.