From Wikipedia, the free encyclopedia
Temporal range: Late Pleistocene–Holocene
|Photo and restoration of skull|
TaxonomyHaast's eagle was first described by Julius von Haast in 1871 from remains discovered by F. Fuller in a former marsh. Haast named the eagle Harpagornis moorei after George Henry Moore, the owner of the Glenmark Estate, where the bones of the bird had been found. The genus name is from the Greek "harpax", meaning "grappling hook", and "ornis", meaning "bird".
EvolutionDNA analysis has shown that this raptor is related most closely to the much smaller little eagle as well as the booted eagle and not, as previously thought, to the large wedge-tailed eagle. Thus, Harpagornis moorei may eventually be reclassified as Hieraaetus moorei. H. moorei is estimated to have diverged from these smaller eagles as recently as 1.8 million to 700,000 years ago. If this estimate is correct, its increase in weight by ten to fifteen times is an exceptionally rapid weight increase. This was made possible in part by the presence of large prey and the absence of competition from other large predators.
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.
While most bones studied have been internal ones, some remains of Haast's eagles allow people to make comparisons to living eagles. The harpy eagle (Harpia harpyja) and the Philippine eagle (Pithecophaga jefferyi), 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. A lower mandible from the Haast's eagle measured 11.4 cm (4.5 in) and the tarsus in several Haast's fossils has been measured from 22.7 to 24.9 cm (8.9 to 9.8 in). In comparison, the largest beaks of eagles today (from the Philippine and the Steller's sea eagle) reach a little more than 7 cm (2.8 in); and the longest tarsal measurements (from the Philippine and the Papuan eagle) top out around 14 cm (5.5 in). 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). The Philippine eagle might make for particularly apt living species to compare the Haast's eagle with, because it too evolved in an insular environment from smaller ancestors (apparently basal snake eagles) to island gigantism in the absence of large carnivorous mammals and other competing predators. 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 in) in female specimens, and very broad. This characteristic would compensate for the reduction in wing area by providing additional lift. 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.
Until recent human colonisation that introduced rodents and cats, the only mammals found on the islands of New Zealand were three species of bat. 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.
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 by around 1400. The loss of its primary prey caused the Haast's eagle to become extinct at about the same time.
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; but they may have been Eyles' harriers.
Relationship with humans
Artwork depicting Haast's eagle now may be viewed at OceanaGold's Heritage and 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.
|Wikispecies has information related to: Harpagornis moorei|
- Martinson, Paul (2006). "Haast's Eagle. Harpagornis moorei". Wellington: Te Papa Press.
Artwork produced for the book Extinct Birds of New Zealand by Alan Tennyson
- Wingspan Birds of Prey Trust
- "Haast Eagle". New Zealand Birds Limited.
- "New Zealand Eagle". NZ Conservation Trust.
Charles Douglas' reputed sighting
- "Harpagornis Moorei". Te Papa Tongarewa: Museum of New Zealand.
- Haast's Eagle on BBC