Haast's eagle was the largest eagle ever to have lived. Any larger, and it would not have been able to fly. It was also unusual because it was the top predator in a unique eco-system or food chain - one which was made up of only birds.
Bones of the eagle have been found in more than 50 places, mostly in the east and south of the South Island. Some are estimated to be only 500 years old, showing that eagles and humans were alive together. Other bones are up to 30,000 years old.
Julius von Haast, first director of the Canterbury Museum, was the first to describe bones found in the Glenmark Swamp in 1871. The most complete eagle skeleton was recovered from a cave on Mount Owen in northwest Nelson in 1990. Because eagle bones were found with moa bones in the Glenmark Swamp, it is believed that the eagle may have preyed on moas which were stuck in the swamp.
Environment and behaviour
Compared to other birds of prey, it had short but powerful wings for the size of its body, with a wingspan of up to 3 metres. This probably meant that it "flapped" rather than "soared". This also fits with the theory that Haast's eagle was a forest bird, used to flying quickly through thick vegetation. The Canterbury Plains were once a combination of forest, scrublands and grasslands, with drier forested areas than on the West Coast.
Females (the larger of the eagle pair) probably weighed about 13 kilograms, and males about 10 kilograms. It also had extremely strong legs, with enormous talons of up to 60 mm long, and a vicious beak it used to tear flesh from its prey. The shape of this beak suggests that, like a vulture, Haast's eagle would feed deep inside the carcass of its prey.
Haast's eagle probably hunted by watching for prey from a high perch and then swooped down onto its victim. It would use its powerful claws to grab the moa's hindquarters and then kill it by crushing the bone and puncturing the internal organs. A number of moa fossils show extensive damage from eagle claws. It is estimated that the combined strength of the legs, feet and claws would have meant that Haast's eagle would been able to kill a moa weighing 200 kilograms.
Other sources of food probably included larger birds, such as duck, rail, weka and pigeon. Moa would have been killed only occasionally, as too much predation would have wiped them out earlier, and it is known that moa and eagle co-existed for at least 120,000 years.
The causes of the eagle's extinction are those of other extinct species - loss of prey and habitat destruction. The coming of the Māori to New Zealand was probably a decisive factor. Once the larger birds, including the moa, were killed off by the Māori, Haast's eagle would have been unable to find enough large prey to keep it alive. It would have been competing with people for the same food.
By the mid 14th century most of the lowland habitat of Haast's eagle would have been destroyed by fire or hunted out. Haast's eagle was still in existence when Māori came to New Zealand, but it is not certain when it died out, although there are reports of a large bird being seen in the nineteenth century.
- Haast's Eagle resources in our catalogue
- Extinct New Zealand bird resources in our catalogue
- The lost world of the moa T. H. Worthy
- The natural world of New Zealand: an illustrated encyclopaedia of New Zealand's natural heritageopens a new window Gerard Hutching
- Haast's Eagle from Wingspan: National Bird of Prey Centre
- Giant eagle (Aquila moorei), Haast's Eagle or Pouakai Te Papa Tongarewa
- Haast’s Eagle NZ birds online
- New Zealand’s birds of prey Te Ara
- Our full list of New Zealand Birds and Animals