Haast's eagle

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Haast's Eagle
Scientific classification
Kingdom Information
Domain Eukaryota
Kingdom Animalia
Subkingdom Bilateria
Branch Deuterostomia
Phylum Information
Phylum Chordata
Sub-phylum Vertebrata
Infraphylum Gnathostomata
Class Information
Superclass Tetrapoda
Class Aves
Sub-class Neornithes
Infra-class Neoaves
Order Information
Superorder Passerimorphae
Order Accipitriformes
Infraorder Falconides
Family Information
Family Accipitridae
Sub-family Buteoninae
Genus Information
Genus Harpagornis
Species Information
Species H. moorei
Population statistics
Conservation status Extinct

Haast's eagle (Harpagornis moorei), bird of prey formerly of New Zealand, and extinct since 1440. Haast's eagle has the distinction of being the largest known eagle on record, the subject of Maori legends of man-killing birds. The bird was named for New Zealand geologist and explorer Julius von Haast.

Description

Three known mounted skeletons reside in New Zealand museums, and from these estimates have been made about the overall size of Haast's eagle. At minimum they are some 30% heavier than the largest living bird of prey, the harpy eagle (Harpia harpyja). As in other raptors, females were larger than males; in weight alone it was estimated to be 25.35 pounds for a male, over 30 pounds for a female[1]. Its wingspan was between 8.5 to 9 feet, but in terms of flight Haast's eagle was built more like harpy - i.e. short, rounded wings and long tail of forest eagles - than the longer wings and short tails of open country raptors like the golden eagle (Aquila chrysaetos).

Haast's eagles hunted large game, primarily moas, but other birds were also part of their diet, such as flightless geese (Cnemiornis spp) and the adzebills (Aptomis spp). As in harpies, Haast's eagles probably used a still-hunt approach; they would sit on a high branch and wait for game to appear, then would suddenly swoop upon it. The impact of an eagle striking a moa would knock the prey animal off its feet, and fractures of pelvises, neck bones, and skulls indicate the killing power of the talons.

Extinction

About the year 1280 the first humans arrived in New Zealand, encountering no other large animals on the islands other than the moas, which they began to hunt relentlessly, resulting in the extinction of these birds by 1440. The demise of the moa left Haast's eagles with no large prey; they possibly hunted humans during the time of Maori colonization and sometime after the moa extinction, leading to legends of the man-eating birds hokioi and poukai being handed down through oral tradition[2]. Maori did kill them, as their bones have been found in midden dumps[3].

Some 400 years after the eagle's extinction a noted explorer, Charles Edward Douglas, had encountered two very large raptors in the Landsborough River valley (possibly between 1870-1880), shooting them for food. He described them:

The expanse of wing of this bird will scarcely be believed. I shot two on the Haast, one was 8 feet 4 inches (2.54 m) from tip to tip, the other was 6 feet 9 inches (2.06 m), but with all their expanse of wing they have very little lifting power, as a large hawk can only lift a duck for a few feet, so no one need get up any of those legends about birds carrying babies out of cradles, as the eagle is accussed [sic] of doing[4]

What Douglas may have shot was another extinct raptor, Eyles' harrier.

References

  1. http://notornis.osnz.org.nz/system/files/Notornis_39_4_239.pdf
  2. http://www.independent.co.uk/environment/nature/maori-legend-of-man-eating-bird-is-true-1786867.html
  3. http://www.nzbirds.com/birds/haasteagle.html
  4. Grzelewski 1996, pp. 24–45
  • Grzelewski, Derek. "Travels with 'Mr. Explorer' Douglas"; article in New Zealand Geographic Magazine, October-December, 1996.