New Zealand raven

The New Zealand raven (Corvus moriorum) was native to New Zealand, but has been extinct since the 16th century. There were three subspecies: the North Island raven (Corvus moriorum antipodum), South Island raven (Corvus moriorum pycrafti), and Chatham raven (Corvus moriorum moriorum) from the Chatham Islands.

The holotype of the South Island raven (formerly Corvus antipodum pycrofti) is in the collection of the Museum of New Zealand Te Papa Tongarewa.

New Zealand ravens were large corvids with long, broad bills that were not as arched as those of some of the Hawaiian crows (Corvus hawaiiensis).

Remains of New Zealand ravens are most common in Pleistocene and Holocene coastal sites. On the coast, it may have frequented seal and penguin colonies or fed in the intertidal zone, as does the Tasmanian forest raven Corvus tasmanicus. It may also have depended on fruit, like the New Caledonian crow Corvus moneduloides, but it is difficult to understand why a fruit eater would have been most common in coastal forest and shrubland when fruit was distributed throughout the forest.

DNA evidence suggests that its closest relatives are in the clade containing the forest raven, little raven and Australian raven, from which it split around 2 million years ago. The morphology and ossification of the palate is unusual among corvids, suggesting a unique dietary adaption, perhaps for scavenging large hard food items.

A late Holocene fossil bone of Corvus antipodum was found on Enderby Island in 1964 by New Zealand biologist Elliot Dawson. It is the only authentic record of a corvid in the Auckland Islands and is thought to represent an individual bird that reached the Auckland Islands as a vagrant.

Taxonomy
2017 genetic research determined that the three raven populations were subspecies rather than separate species, having only split 130,000 years ago.

Specimens
A reconstruction of the raven is in the Museum of New Zealand Te Papa Tongarewa, specimen MNZ S.036749.

Description and ecology
The Chatham raven was significantly larger than the New Zealand raven, and probably the world's fourth- or fifth-largest passerine. They had long, broad bills that were not as arched as those of some of the Hawaiian crows (C. hawaiiensis). Presumably, they were black all over like all their close relatives. There do not seem to be recorded oral traditions of this sub-species – most of the Moriori people, after whom this sub-species was named, were eventually killed or enslaved by Māori explorers, and little of their natural history knowledge has been preserved. Thus, it cannot be completely ruled out that like some congeners they had partially white or grey plumage (see also Pied raven).

Remains of Chatham ravens are most common in coastal sites on the Chatham Islands. On the coast, it may have frequented the seal and penguin colonies or fed in the intertidal zone, as does the Tasmanian forest raven (C. tasmanicus). It may also have depended on fruit, like the New Caledonian crow (C. moneduloides), but it is difficult to understand why a fruit eater would have been most common in coastal forest and shrubland when fruit was distributed throughout the forest.