New Zealand Raven
The Maori New Zealand crow or crow ( Corvus antipodum ) is an extinct species of corvids ( Corvidae ). She was one of the largest members of the genus of crows and ravens (Corvus ) and was characterized by an elongated, relatively straight beak and long legs. The Maori Crow occurred on the North and in the South Island of New Zealand. She was probably a bird of open and semi- open country and had perhaps the seashore habitat. Build and localities of the remains suggest along with the original geography of New Zealand suggests that the Maori Crow put an opportunistic feeding behavior of the day.
The Subfossil the type were discovered in the late 19th century and described in 1893 by Henry Ogg Forbes, which they then presented to the genus " Palaeocorax ", which also included the Chathamraben (C. moriorum ). Later authors came to the conclusion that both types were typical of the genus Corvus crows. They probably came from a settlement by an Australian type, probably the Neuhollandkrähe (C. coronoides ), which took place in the Pleistocene at the latest. The Maori Crow came in two subspecies of New Zealand, which were separated by the Cook Strait. She survived until the early days of the settlement of New Zealand by the Maori and died from before the arrival of Europeans.
- 6.1 Literature
- 6.2 External links
- 6.3 Notes and references
Features
The Maori Crow was a huge Krähenart and exceeded with the exception of Chathamrabens (C. moriorum ) all current Australasian Crows in body size. The fossil material of the kind, although numerous, but often receive only fragmentary, so conclusions about the appearance are not always possible. The beak was long, wide and relatively straight. She was a little smaller than the Chatham - Iceland - Raven, but still one of the largest species of the genus Corvus. The weight of the Maori Crow is estimated at 0.9-1.0 kg, so that they would be about as heavy as an African -necked Raven (C. albicollis ) become. The ratio of wing length to leg length was slightly smaller than in the living species today crows. This suggests that the Maori crow was at least easily adapted to an environment without Bodenprädatoren, although she kept her flying. However, this trend was not as strong as pronounced in Chathamraben. In body size, there were clear differences between the North and South Islands: Maori crows were greater than in the north to the south. The leg bones found in the South Island in the Middle measure 71 mm, on the North Island, however, only 68 mm. Similar conditions apply to the other parts of the skeleton. The variation was klinal from the warmer north in the colder south, thereby complying with the Bergmann's rule. In the Pleistocene, the birds in the middle were the same as in the Holocene, but had a larger variance.
Distribution and habitat
The Maori Crow was located on the North and South Islands of New Zealand. The fossil record shows Pleistocene and Holocene between a noticeable difference: While both north and south of the Cook Strait find the type in the Pleistocene fossil sites in both, it is absent in the Holocene deposits in the North Island. It has been found in archaeological sites from the early days of the Maori there, however. For the Pleistocene specimens are mainly on the west coast and the eastern tip of the North Island. For the Holocene, the Maori crow with the exception of the southwestern South Island is also handed down from the east coast.
All Locations are spread out along the coast of the islands of New Zealand, no bones were located further inland deposits found so far. This suggests that the Maori Crow was a coastal residents. That most dated to the Holocene finds from the low forest east coast of New Zealand come, indicates open landscapes or forest edges down as a habitat.
Way of life
The lifestyle of the Maori Crow should have complied with the extant large crows. When unspecialized coastal residents fed them probably omnivorous fruit, large insects, terrestrial vertebrates, and the eggs and young of seabird colonies. Richard Holdaway suggested, moreover, that the Maori Crow also on carcasses from Haastadler ( Hapagornis moorei ) batted birds ate and considers it possible that she stalked Moaküken. It is possible beyond even that kind combed through the mud at low tide. The physique of the Maori Crow suggests no special adaptation, even if it was probably a passable runners by their relatively long legs. After Holdaway the nest was probably built of sticks and placed in trees or rock crevices. This is contradicted by Brian Gill, in his assumption that Maori Crow was a ground-nesting birds, or at least have bred at low altitude, because their extinction is different do not explain.
Systematics and evolution
Taxonomy
The first remains of Maori Crow discovered in the 19th century. Henry Ogg Forbes held the larger bone of the South Island first for remains of Chathamraben. The significantly smaller bone of the North Island, however, he described in 1893 as a separate species Palaeocorax antipodum and placed it near the Chathamraben. The specific epithet antipodum respect to. Probably to New Zealand as antipodes of Europe A holotype was not to Forbes, which should prove to be problematic later. As with many other species described by Forbes later authors could not understand what bone he had used for his depictions of what antipodum the validity of the taxon Corvus questioned. William Pycraft who examined the Chathamraben, doubted in view of the osteological features on the authorization of a separate genus " Palaeocorax " Pierce Brodkorb finally synonymisierte with Corvus and explained the Maori crow to a subspecies of Chathamraben. Brian Gill underwent bone of the North Island, the South Island and Chatham in 2003 a detailed comparison and came to the conclusion that at Chatham and the main islands each have their own style was based. He put the smaller North and the larger Südform in each a separate subspecies, and had both a lectotype to. To clearly distinguish the two taxa from Chathamraben, he chose to specifically each small specimens as types.
Outer systematics
For the settlement of New Zealand just a few crows species occur due to the great distance to the nearest major land mass in question, which might be the closest relatives of Maori crow. What is certain is that it is closely related to the Chathamraben (C. moriorum ) and a direct common ancestor has with him. That to Chatham and the main islands developed two different types, can also be observed in some other endemic species in New Zealand. For the colonization of the islands are on the one hand Australian crow species, on the other hand, the New Caledonian New Caledonian crow (C. moneduloides ) in question. Brian Gill holds the Neuhollandkrähe (C. coronoides ) living in the south west of Australia for the next of kin of the Maori crow, because it comes to their body size of all neighboring species closest.
Inside systematics
Similar to some other New Zealand bird species introduced Gill to two subspecies of the Maori Crow to take account of the size difference between North and South Island.
- Corvus antipodum antipodum - (Forbes, 1893):
- Corvus antipodum pycrafti - Gill, 2003:
Extinction
The exact time at which the extinct Maori Crow is unknown. What is certain is that they disappeared by the Maori in the course of the first settlement of New Zealand. The exact reasons are unclear: As unspecialized, flight omnivores Maori Crow would have actually had a good chance to survive. It is possible, however, that Pacific rats ( Rattus exulans ) and other animals introduced by the Maori the opportunity of the kind afflict strong; provided the Maori Crow was a ground-nesting birds. Another cause for the disappearance of the species may have been the habitat change that went hand in hand with the early development of New Zealand. Since they in prehistoric cooking areas as often occurs as in fossil deposits of the same age, overhunting is unlikely as the cause of their extinction.