Haast's Eagle Conservation status: Extinct (c1500)
Artist's rendition of Harpagornis attacking moas
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Order: Falconiformes Family: Accipitridae Genus: Harpagornis Species: moorei
Binomial name
Harpagornis moorei Haast, 1872

The Harpagornis or Haast's eagle was a massive New Zealand eagle and the largest bird of prey known to have lived. It is believed that Maori called it Pouakai or Hokioi.

Female Harpagornis weighed 10 to 14 kilograms (22 to 30 pounds) and males 9 to 10 kilograms. They had a wingspan of about 3 meters which is short for a bird of that weight but which allowed 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, Harpagornis could have fed on a single large kill over a number of days.

Early human settlers in New Zealand (Maori 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 Harpagornis became extinct 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 Maori.

In effect, birds occupied all positions in the New Zealand animal ecology. Moa filled a grazing niche occupied elsewhere by deer or cattle, and the harpagornis occupied the same niche as carnivorous hunters such as wolves, leopards or tigers. For this reason, they have sometimes been termed leopard eagles.

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. Harpagornis may have diverged from the small eagles about one 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.

See also

• Extinct birds

External links

• (2005) Ancient DNA Tells Story of Giant Eagle Evolution. (http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371%2Fjournal.pbio.0030020) PLoS Biol 3(1): e20.
• New Zealand Giant Eagle (http://www.bbc.co.uk/nature/wildfacts/factfiles/3044.shtml)
• Pouakai, the Haast Eagle (http://www.nzbirds.com/Harpogornis.html)
• Ancient DNA Provides New Insights into the Evolutionary History of New Zealand's Extinct Giant Eagle (http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0030009)