Because the original fauna of New Zealand contained no mammals, these islands were often called “The Land of Birds”. Such a title has long been inappropriate, as introduced mammals now rule the land in much the same way as they do elsewhere – but for aeons birds represented the dominant lifeform. Quite why mammals were originally excluded from this corner of the planet is one of the mysteries of prehistory, but excluded they certainly were. In the land now known as New Zealand, birds adapted to fill many of the niches more familiarly occupied by mammals. The most spectacular of these creatures were the birds now known as moas. There were a number of species and argument rages today over just how many.
Some authorities put the figure as low as 10, others identify 30 or 40; such controversy is typical of the kind of difficulty experienced when ornithologists try to make sense of osteological material and have little else to go on. In the case of the moas there are some skin and feather fragments as well as a very few eggs and egg pieces, but these remains are tantalizing and reveal little of significance. The largest of the moas, Dinornis giganteus, was the tallest known bird ever and it raised its head, upon a long serpentine neck, to the extraordinary height of around 4 m. Although not as hugely ponderous as the Madagascan Great Elephantbird, this was a considerably taller creature and presumably it must have been an awe-inspiring sight.
The evidence suggests that this particular species was probably gone by 1600 but it seems probable that a smaller – but still gigantic – relative, Dinornis torosus, survived after this date. There is, in fact, much controversy over the date at which the last of the moas became extinct. Some argue that this was at a comparatively antique time, others suggest the extinction was much more recent. A fragment of bone from Dinornis torosus seems to have been the first moa relic to come to the attention of ornithologists. This was in 1839 when the celebrated comparative anatomist Richard Owen stuck his neck out and made his famous announcement that there had lived in New Zealand – or even perhaps at that time still lived – a gigantic bird similar to an Ostrich. Owen based this deduction on a very small fragment of bone that had been brought to him for identification by a Dr John Rule.
Despite the unpleasant things that are often said of him, Owen was certainly not lacking in courage: had he been proved wrong, his reputation, and indeed his whole career, would have been in tatters. However, only a short time after his sensational announcement, solid proof, in the form of skeletons, came to light and proved his deductions to have been accurate. Bones of D. torosus have been found at widely scattered localities on New Zealand’s South Island. Their comparative rareness in swamp deposits suggests that the species may have preferred hill country. Some of the tops of the skulls of this species show deep pits in the surface and this may indicate that birds carried crests.
New Zealand J. Sci. 1(6): 2476