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'''Haast's Eagle''' (''Harpagornis moorei'') is an [[extinct (biology)|extinct]] species of [[eagle]] that once lived on the [[South Island]] of [[New Zealand]], commonly accepted to be the '''Pouakai''' of Maori legend.<ref name="collections.tepapa.govt.nz">[http://collections.tepapa.govt.nz/theme.aspx?irn=1360 Giant eagle (Aquila moorei), Haast’s eagle, or Pouakai]. Museum of New Zealand: Te Papa Tongarewa. Retrieved 27 October 2010.</ref> The species was the largest eagle known to have existed. Its prey is suspected to consist of [[moa]]. This eagle's massive size may have been an evolutionary response to the size of its prey, as both would have been much smaller when they first came to the island, and would have grown larger over time due to lack of competition (see [[island gigantism]]). Haast's Eagle became [[extinction|extinct]] around the year 1400, when its major food source, the [[moa]], were hunted to extinction by Maori, and much of its dense-forest habitat was cleared.
'''Haast's Eagle''' (''Harpagornis moorei'') is an [[extinct (biology)|extinction]] species of [[eagle]] that once lived on the [[South Island]] of [[New Zealand]], commonly accepted to be the '''Pouakai''' of Maori legend.<ref name="collections.tepapa.govt.nz">[http://collections.tepapa.govt.nz/theme.aspx?irn=1360 Giant eagle (Aquila moorei), Haast’s eagle, or Pouakai]. Museum of New Zealand: Te Papa Tongarewa. Retrieved 27 October 2010.</ref> The species was the largest eagle known to have existed. Its prey is suspected to consist of [[moa]]. This eagle's massive size may have been an evolutionary response to the size of its prey, as both would have been much smaller when they first came to the island, and would have grown larger over time due to lack of competition (see [[island gigantism]]). Haast's Eagle became [[extinction|extinct]] around the year 1400, when its major food source, the [[moa]], were hunted to extinction by Maori, and much of its dense-forest habitat was cleared.


==Classification==
==Classification==

Revision as of 10:29, 6 July 2013

Haast's Eagle
Photo and restoration of skull

Extinct (1400)  (IUCN 3.1)
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Aves
Order:
Accipitriformes
Family:
Accipitridae
Genus:
†Harpagornis
Species:
†H. moorei
Binomial name
Harpagornis moorei
Haast, 1872

Haast's Eagle (Harpagornis moorei) is an extinction species of eagle that once lived on the South Island of New Zealand, commonly accepted to be the Pouakai of Maori legend.[1] The species was the largest eagle known to have existed. Its prey is suspected to consist of moa. This eagle's massive size may have been an evolutionary response to the size of its prey, as both would have been much smaller when they first came to the island, and would have grown larger over time due to lack of competition (see island gigantism). Haast's Eagle became extinct around the year 1400, when its major food source, the moa, were hunted to extinction by Maori, and much of its dense-forest habitat was cleared.

Classification

Comparative morphology of Haast's Eagle with its closest living relative, the Little Eagle

DNA analysis has shown that this raptor is related most closely to the much smaller Little Eagle as well as the Booted Eagle (both of these two species were recently reclassified as belonging to the genus Aquila [2]) and not, as previously thought, to the large Wedge-tailed Eagle.[3] Thus, Harpagornis moorei may eventually be reclassified as Aquila moorei. H. moorei may have diverged from these smaller eagles as recently as 700,000 to 1.8 million years ago. Its increase in weight by ten to fifteen times over that period is the greatest and quickest evolutionary increase in weight of any known vertebrate. This was made possible in part by the presence of large prey and the absence of competition from other large predators [citation needed].

Etymology

Haast's Eagle was first described by Julius von Haast in the 1870s,[4] who named it Harpagornis moorei after George Henry Moore, the owner of the Glenmark Estate where bones of the bird had been found. The genus name is from the Greek "harpax", meaning 'grappling hook', and "ornis", meaning 'bird'.

Size and habits

Artist's rendition of a Haast's Eagle attacking moa

Haast's Eagles were the largest known true raptors, slightly larger even than the largest living vultures. Female eagles are significantly larger than males. Most estimates place the female Haast Eagles in the range of 10–15 kg (22–33 lb) and males around 9–12 kg (20–26 lb).[5] A comparison to living eagles of the Australasian region resulted in estimated masses in Haast's Eagles of 11.5 kg (25 lb) for males and 14 kg (31 lb) for females.[6] One source estimates that the largest females could have scaled more than 16.5 kg (36 lb) in mass.[7] They had a relatively short wingspan for their size. It is estimated that the grown female typically spanned up to 2.6 m (8.5 ft), possibly up to 3 m (9.8 ft) in a few cases.[8][9] This wingspan is broadly similar to the larger range of female size in some extant eagles: the Wedge-tailed Eagles (Aquila audax), Golden Eagles (A. chrysaetos), Steppe Eagles (A. nipalensis), Martial Eagles (Polemaetus bellicosus) and Steller's Sea Eagles (Haliaeetus pelagicus).[10][11] However, even the largest extant eagles, none of which are verified to exceed 9 kg (20 lb) in a wild state, are about forty percent smaller in body size than Haast's Eagles.[10] Several of the largest extant Old World vultures, if not in mean mass or other linear measurements, probably exceeded Haast's Eagle in average wingspan.[10][12]

Short wings may have aided Haast's Eagles when hunting in the dense scrubland and forests of New Zealand. Haast's Eagle has sometimes been portrayed incorrectly as having evolved toward flightlessness, but this is not so; rather it represents a departure from the mode of its ancestors' soaring flight, toward higher wing loading and the species probably had very broad wings.[13]

While most bones studied have been internal ones, some remains of Haast's Eagles allow us to make comparisons to living eagles. The Harpy Eagle and the Philippine Eagle, which are the largest and most powerful living eagles alongside the Steller's Sea Eagle, also have similarly reduced relative wing-length in adaptation to forest-dwelling.[10] A lower mandible from the Haast's Eagle measured 11.4 cm (4.5 in) and while the tarsus in several fossils has been measured from 22.7 to 24.9 cm (8.9 to 9.8 in).[14] In comparison, the largest beaked eagles today (the Philippine and the Steller's Sea Eagle]]) reach a little more than 7 cm (2.8 in) and the longest tarsal measurement (from the Philippine and the Papuan Eagle) top out around 14 cm (5.5 in).[12][15][16] The talons of the Haast's Eagle were similar in length those of the Harpy Eagle, with a front-left talon length of 4.9 to 6.15 cm (1.93 to 2.42 in) and a hallux-claw of possibly up to 11 cm (4.3 in).[7] The strong legs and massive flight muscles of these eagles would have enabled the birds to take off with a jumping start from the ground, despite their great weight. The tail was almost certainly long, in excess of 50 cm (20 inches) in female specimens, and very broad. This characteristic would compensate for the reduction in wing area by providing additional lift.[5] Total length is estimated to have been up to 1.4 m (4 ft 7 in) in females, with a standing height of approximately 90 cm (2 ft 11 in) tall or perhaps slightly greater.[7]

Haast's Eagles preyed on large, flightless bird species, including the moa, which was up to fifteen times the weight of the eagle.[5] It is estimated to have attacked at speeds up to 80 km/h (50 mph),[17][better source needed] often seizing its prey's pelvis with the talons of one foot and killing with a blow to the head or neck with the other.[citation needed] Its size and weight indicate a bodily striking force equivalent to a cinder block falling from the top of an eight-story building.[18] Its large beak also could be used to rip into the internal organs of its prey and death then would have been caused by blood loss.[citation needed] In the absence of other large predators or scavengers, a Haast's Eagle easily could have monopolised a single large kill over a number of days.[1]

Maori legendry

It is believed that these birds are described in many legends of the Māori, under the names Pouakai, Hokioi, or Hakawai.[4] However, it has been ascertained that the "Hakawai" and "Hokioi" legends refer to the Coenocorypha snipe – in particular the extinct South Island subspecies.[19] According to an account given to Sir George Grey, an early governor of New Zealand, Hokioi were huge black-and-white predators with a red crest and yellow-green tinged wingtips. In some Māori legends, Pouakai kill humans, which scientists believe could have been possible if the name relates to the eagle, given the massive size and strength of the bird.[4]

Extinction

A model on display at Te Papa of a Haast's Eagle attacking a moa with its large talons

Early human settlers in New Zealand (the Māori arrived around the year 1280) preyed heavily on large flightless birds, including all moa species, eventually hunting them to extinction. The loss of its natural prey caused the Haast's Eagle to become extinct as well around the year 1400,[20] when the last of its natural food sources were depleted.

A noted explorer, Charles Edward Douglas, claims in his journals that he had an encounter with two raptors of immense size in Landsborough River valley (probably during the 1870s), and that he shot and ate them.[21] These birds might have been a last remnant of the species, but some might argue that there had not been suitable prey for a population of Haast's Eagle to maintain itself for about five hundred years before that date, [citation needed] and 19th century Māori lore was adamant that the pouakai was a bird not seen in living memory. Still, Douglas' observations on wildlife generally are trustworthy; a more probable explanation, given that the alleged three-metre wingspan described by Douglas is likely to have been a rough estimate, is that the birds were Eyles' Harriers. This was the largest known harrier (the size of a small eagle) — and a generalist predator — and although it also is assumed to have become extinct in prehistoric times, its dietary habits alone make it a more likely candidate for late survival.[original research?]

Until recent human colonisation that introduced rodents and cats, the only mammals found on the islands of New Zealand were three species of bat, one of which recently has become extinct. Free from terrestrial mammalian competition and predatory threat, birds occupied or dominated all major niches in the New Zealand animal ecology because there were no threats to their eggs and chicks by small terrestrial animals. Moa were grazers, functionally similar to deer or cattle in other habitats, and Haast's Eagles were the hunters who filled the same niche as top-niche mammalian predators, such as tigers or lions.

In art

Artwork depicting Haast's Eagle now may be viewed at OceanaGold's Heritage & Art Park at Macraes, Otago, New Zealand. The sculpture, weighing approximately 750 kg (1,650 lb; 118 st), standing 7.5 metres (25 ft) tall, and depicted with a wingspan of 11.5 metres (38 ft) is constructed from stainless steel tube and sheet and was designed and constructed by Mark Hill, a sculptor from Arrowtown, New Zealand.[22]

See also

References

  1. ^ a b Giant eagle (Aquila moorei), Haast’s eagle, or Pouakai. Museum of New Zealand: Te Papa Tongarewa. Retrieved 27 October 2010.
  2. ^ Lerner, H. R. L. (2005). "Phylogeny of eagles, [[Old World vulture]]s, and other Accipitridae based on [[Nuclear DNA|nuclear]] and [[mitochondrial DNA]]" (PDF). Molecular Phylogenetics and Evolution. 37 (2): 327–346. doi:10.1016/j.ympev.2005.04.010. PMID 15925523. {{cite journal}}: URL–wikilink conflict (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  3. ^ Bunce, M. (2005). "Ancient DNA Provides New Insights into the Evolutionary History of New Zealand's Extinct Giant Eagle". PLoS Biology. 3 (1): e9. doi:10.1371/journal.pbio.0030009. PMC 539324. PMID 15660162. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: unflagged free DOI (link)
  4. ^ a b c Rodgers, Paul (14 September 2009). "Maori legend of man-eating bird is true". The Independent. Retrieved 14 September 2009. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
  5. ^ a b c Brathwaite, D. H. (1992). "Notes on the weight, flying ability, habitat, and prey of Haast's Eagle (Harpagornis moorei)" (PDF). Notornis. 39 (4): 239–247. Ornithology of the Southern Pacific {{cite journal}}: Unknown parameter |month= ignored (help)
  6. ^ Braithwaite, D.H. "NOTES ON THE WEIGHT, FLYING ABILITY, HABITAT, AND PREY OF HAAST'S EAGLE (Harpagornis moorei)" (PDF). Notornis, journal of the Ornithological Society of New Zealand (Inc.). Retrieved 28 March 2013.
  7. ^ a b c Worthy, T. & Holdaway, R., The Lost World of the Moa: Prehistoric Life of New Zealand. Indiana University Press (2003), ISBN 978-0253340344
  8. ^ Maas, P. "Recently Extinct Animals - Species Info - Haast's Eagle". The Sixth Extinction. Retrieved 19 April 2013.
  9. ^ "Haast's Eagle". Paleobiology and Biodiversity Research Group. Retrieved 19 April 2013.
  10. ^ a b c d Wood, Gerald (1983). The Guinness Book of Animal Facts and Feats. ISBN 978-0-85112-235-9.
  11. ^ Eagles, Hawks and Falcons of the World by Leslie Brown & Dean Amadon. The Wellfleet Press (1986), ISBN 978-1555214722.
  12. ^ a b Ferguson-Lees, J.; Christie, D. (2001). Raptors of the World. London: Christopher Helm. ISBN 0-7136-8026-1.{{cite book}}: CS1 maint: multiple names: authors list (link)
  13. ^ Haast’s eagle, New Zealand giant eagle, BBC. Retrieved 27 October 2010.
  14. ^ Hamilton, A. 1888. On Avian Remains in Southland. Transactions, The New Zealand Institute.
  15. ^ Ladyguin, Alexander (2000). The morphology of the bill apparatus in the Steller’s Sea Eagle. First Symposium on Steller’s and White-tailed Sea Eagles in East Asia pp. 1–10; Ueta, M. & McGrady, M.J. (eds.) Wild Bird Society of Japan
  16. ^ Blas R. Tabaranza Jr. "Haribon – Ha ring mga Ibon, King of Birds". Haring Ibon’s Flight…. Retrieved 2013. {{cite web}}: Check date values in: |accessdate= (help)
  17. ^ Paul Rodgers. Maori legend of man-eating bird is true, Independent.ie, 14 September 2009. Retrieved 27 October 2010.
  18. ^ Kennedy Warne. Hotspot: New Zealand, National Geographic Magazine, October 2002. Retrieved 27 October 2010.
  19. ^ Miskelly, C. M. (1987). "The identity of the hakawai" (PDF). Notornis. 34 (2): 95–116.
  20. ^ Tennyson, A. (2006). Extinct Birds of New Zealand. Wellington, New Zealand: Te Papa Press. ISBN 978-0-909010-21-8. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  21. ^ Worthy, T. H. (2002). The lost world of the Moa: Prehistoric Life of New Zealand. Bloomington: Indiana University Press. ISBN 0-253-34034-9. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  22. ^ "Giant art sculptures pop up in Otago". New Zealand: 3 News. 20 December 2008. Lifestyle - Video On Demand text version
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