Haast's Eagle

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{{Taxobox | color = pink | name = Haast's Eagle | status = Conservation status: Extinct{{#if:{{{when|}}}| (c. AD 1500) }} | image = Giant_Haasts_eagle_attacking_New_Zealand_moa.jpg | image_width = 220px | image_caption = Artist's rendition of a Haast's Eagle attacking moa | regnum = Animalia | phylum = Chordata | classis = Aves | ordo = Falconiformes | familia = Accipitridae | genus = Harpagornis | species = H. moorei | binomial = Harpagornis moorei | binomial_authority = Haast, 1872 }}Image:Haastseagleattacksamoa.jpg The Haast's Eagle (Harpagornis moorei) was a massive eagle that once lived on the South Island of New Zealand. After the extinction of the teratorns, the Haast's Eagle was the largest bird of prey in the world. It is believed that Māori called it Pouakai or Hokioi.

Female Haast's Eagles weighed 10 to 14 kilograms (22 to 30 pounds), and males weighed 9 to 10 kilograms. They had a wingspan of about 2.6 - 3 meters, which is short for a bird of the Haast's Eagle's weight, but permitted them to hunt in forests. It preyed on large, flightless birds species including moa up to 15 times its weight. It attacked moa at speeds up to 80 kilometers per hour (50 mph), seizing a moa by the pelvis with the talons of one foot and killing it with a blow to the head or neck with a talon of the other foot. In the absence of other large predators or scavengers, a Haast's Eagle could have fed on a single large kill over a number of days.

Early human settlers in New Zealand (Māori arrived about 1000 years ago) also preyed heavily on large, flightless birds and hunted some of them, including all the moa species, to extinction. The Haast's Eagle became extinct around 1400 AD along with its prey. It may also have been hunted itself by humans: a large, fast bird of prey that specialized in hunting large bipeds may have been perceived as a threat by Māori.

Until recent human colonisation, the only terrestrial mammals found on New Zealand were two species of bat. Free from mammalian competition and predatory threat, birds occupied all positions in the New Zealand animal ecology. Moa filled a grazing niche occupied elsewhere by deer or cattle, and the Haast's Eagle occupied the same niche as carnivorous hunters such as wolves, leopards or tigers.

DNA analysis has shown that it is most closely related to the small Little Eagle and Booted Eagle, and not, as previously thought, to the large Wedge-tailed Eagle. In fact, Harpagornis moorei is more closely related to the Little Eagle and Booted Eagle, than these are to other members of the genus Hieraaetus. Thus, Harpagornis moorei should probably be reclassified as Hieraaetus moorei, pending confirmation. H. moorei may have diverged from these small eagles as recently as 700,000 to 1.8 million years ago. Its increase in weight by 10 to 15 times in that period is the greatest and fastest evolutionary increase in weight of any known vertebrate. This was made possible by the presence of large prey and the absence of competition from other large predators.

This bird was first classified by Julius von Haast, who named it Harpagornis moorei after George Henry Moore, the owner of the Glenmark Estate where the bones of the bird had been found.

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