Upland moa

The upland moa (Megalapteryx didinus) is an extinct species of moa that was endemic to New Zealand. It is a ratite, a grouping of flightless birds with no keel on the sternum. It was the last moa species to become extinct, vanishing around 1500 CE, and was predominantly found in alpine and sub-alpine environments.

Taxonomy
The upland moa was named as Dinornis didinus in 1883 by Richard Owen from mummified material found in 1878 by H. L. Squires in Queenstown, New Zealand and sent to the British Museum. The holotype specimen consists of a mummified head and partial neck, and two mummified legs and feet which preserve the feathers.

In 2005, a genetic study suggested that M. benhami, which had previously been considered a junior synonym of M. didinus, may have been a valid species after all.

The cladogram below follows a 2009 analysis by Bunce et al.:

Description
At less than 1 metre tall and about 17 to 34 kilogram in weight, the upland moa was among the smallest of the moa species. Unlike other moas, it had feathers covering all of its body but the beak and the soles of its feet, an adaptation to its cold environment. Scientists believed in the past that the upland moa held its neck and head upright; however, it actually carried itself in a stooped posture with its head level to its back. This would have helped it travel through the abundant vegetation in its habitat, whereas an extended neck would have been more suited to open spaces. It had no wings or tail.

Distribution and habitat
The upland moa lived only on New Zealand's South Island, in mountains and sub-alpine regions. They travelled to elevations as high as 2000 m (7000 ft).

Behavior and ecology
The upland moa was herbivorous, its diet extrapolated from fossilised stomach contents, droppings, and the structure of its beak and crop. It ate leaves and small twigs, using its beak to "shear ... with scissor-like moves". However, bio-mechanical testing of its beak and head has shown it was best suited to feed by pulling backwards, possibly while twisting its head to the side. Its food required grinding before it could be digested, as indicated by its large crop. Studies of the upland moa's coprolites provided evidence that branchlets of trees such as Nothofagus, various lake-edge herbs, tussock, and the nectar-rich flowers made up part of its diet. Based on the pollen present in the coprolites, it is suggested they had a similar lifestyle to the living takahē, feeding in high alpine areas during the summer and descending to lower altitude forests in the winter. They may also have played an important role in the seed dispersal of alpine plants.

This moa usually laid only 1 to 2 blue-green coloured eggs at once, and was likely the only type of moa to lay eggs that were not white in colour. Like the emu and ostrich, male moa cared for the young. The upland moa's only predator before the arrival of humans in New Zealand was the Haast's eagle.

Extinction
Humans first came in contact with the upland moa around 1250 to 1300 AD, when the Māori people arrived in New Zealand from Polynesia. Moa, a docile animal, were an easy source of food for the Māori (who called them "moa pukepuke") and were eventually hunted to extinction in 1445.

Discoveries
The species has the best-preserved mummified remains of any moa species. Several specimens with soft tissue and feather remains are known:
 * British Museum A16, found at Queenstown in 1876, is the type of the species.
 * Otago Museum C.68.2A, leg with much muscle tissue, skin and feathers from the Old Man Range
 * Museum of New Zealand Te Papa Tongarewa NMNZ S.000400, a skeleton with tissue on neck and head from the Cromwell area.
 * Museum of New Zealand Te Papa Tongarewa NMNZ S.023080, a foot with some muscle and sinews, found on 7 January 1987 at Mount Owen. This was dated to be about 3,300–3,400 years old.
 * Museum of New Zealand Te Papa Tongarewa NMNZ S.027950, feathers found in 1949 at Takahe Valley, Fiordland, New Zealand.
 * Canterbury Museum NZ 1725, Remains of one partial egg which have been found at the Rakaia River in 1971 are tentatively attributed to this species. The radiocarbon date of approximately AD 1300–1400 is in line with this. Unusually, the eggshell is dark olive green, but even if the egg is of M. didinus, the shell colour may have varied between individual eggs.
 * Museum of New Zealand Te Papa Tongarewa NMNZ S.023700, complete skeleton found by Trevor Worthy in March 1987 at Honeycomb Hill Cave, Oparara Valley
 * Otago Museum AV10049, skeleton and partial egg found in 2002 at Serpentine Range, Humboldt Mountains.