What Happened to the MOA?

Forest and Bird, Volume 18, Issue 3, 1 August 1987, Page 26

What Happened to the MOA?

by

Barney Brewster

hat happened to the moa? One thousand years ago this remarkable bird was the dominant animal of the New Zealand landscape; now we find it only in museums and crossword puzzles. Moa extinction was the great controversy of New Zealand science last century; this century the disappearance of the moa has been firmly linked to the arrival of the Polynesians, but resistance to this idea was previously strong, and some novel and now quite amusing theories were put forward to explain the demise of the moa. Mass tutu poisoning, the shrinking of southern mossbeds on which the bird was supposed to feed, and the clean sweep of glaciers across the land each had their advocates as the primary cause of extinction. Other writers put the death of the moa down to a general biological malaise.James Drummond, columnist and biology professor at Canterbury University, pontificated in 1907: ‘In the moa, at any rate, we can see the result of laziness and neglect. Life was so easy in New Zealand that it first refrained from flying and then lost the power of flight. It is the emblem of stagnation and decay, and its fate is a shocking example to all who are inclined to give way to slothful habits’. In the 1950s and '60s some scientists talked of the moa having reached the end of its evolutionary life. But it was surely an impossible coincidence that such a large number of other native birds species — and so many of them flightless had attained old age and extinction over the same period. According to modern biology, species do not simply die out through lack of interest or vigour. Any decline in a species must relate to unfavourable changes in the creature’s habitat.

Reluctant to blame

Not all early European observers were blind to the coincidence of the moa’s decline with the arrival of the Maori, their kuri (dog) and kiore (rat). But even to the present day, some have refused to recognise that Polynesian settlers were the most likely cause of the moa’s extinction. As Sir Charles Fleming commented in 1962, ‘it seems we are reluctant to blame our fellow men for a prehistoric offence against modern conservation ideals and would rather blame climate or the animals themselves’.

"On a world-wide scale, there is incredibly strong evidence in New Zealand that the extinction of the moa had human causes," says archaeologist Richard Cassels. ‘‘The human hand is implicated to a fantastic degree.’’ He points out that the case for the human destruction of the many giant marsupials which once roamed Australia is supported by only two archaeological sites, yet a human cause for these extinctions, dating from around fifty thousand years ago, has become generally accepted Excavations in the Oparara caves in the 1980s, and at other places, have added further to the picture of life in New Zealand before human disturbance. Extinct birds found in these caves include the flightless goose, the NZ swan, a flightless duck, the giant flightless rail (Aptornis), other extinct rails, the flightless coot, the giant NZ eagle (Harpagornis), the NZ goshawk, the NZ owletnightjar, and the NZ crow, as well as moa species. Subfossil bone discoveries else-

where show that the nesting or breeding of other animals, such as sea birds and seals, has been restricted. On the Coromandel Peninsula and in the far north, for example, the bones of fur seal pups predate the arrival of European sealers.

The Path to extinction

Of New Zealand's original animals, groundnesting moa were highly visible and vulnerable to new immigrants from Polynesia. That a technologically primitive people, whose numbers seemed tiny compared with the extent of the islands they occupied, could have such an impact on birdlife is at first hard to credit. Joseph Banks, Cook's naturalist, observed in 1770 that over most of the country ‘the number of inhabitants seems to bear no kind of proportion to the size of the country’. In Cook’s time the Maori population was concentrated in the northern North Island, but by far the greatest number of moa hunting sites have been

Ka Tg40 1 te ngaro 0 te Moa' Lost a5 the moa is Iost old Maori proverb

found along the eastern coast of the South Island. In the North Island even coastal sites are not common, with very few moa-hunter sites known from inland. However, other factors may have had a bearing on the apparent lack of moa-hunter sites in the north. A clear association between moa remains and a definite material culture then known as ‘moa hunter’ was not established until schoolboy Jim Eyles’ discovery of the Wairau Bar burials in Marlborough in 1939. Archaeologists now prefer to call the early stage of Polynesian colonisation of New Zealand the Archaic phase, and tend to downplay the role of moa in the diet of these early people. In both islands the evidence for direct hunting of the moa is highly variable from area to area. Although in general it appears that Dinornis was the most common moa hunted in the North Island, and Eurypteryx in the South, the pattern is quite irregular. At one time, for example, it was thought that the moa had been a rare bird in the North Island by the time the Polynesians arrived, but as archaeologist Janet Davidson explains in The Prehistory of New Zealand: ‘It now appears that in parts of the North Island a greater range of moa species was available for longer than in much of the South Island. Even so, there were other parts of the North Island in which moa seem never to have been at all important in the diet’.

Maori traditions

Some hunting techniques are recalled in Maori traditions recorded last century. The moa was said to stand on one leg when attacked, holding the other leg close to the body, poised to strike. A hunter struck by a kick from the bird was likely to be killed. The moa was ‘quite clever at warding off thrusts made at it, with the upraised leg . . . One very effectual way was to strike the leg the bird stood on with a long heavy pole which usually brought it down, when it was killed by spears or clubs’. Other traditional methods included netting, snaring and pit-trapping, which made use of the forest paths of the moa. The earliest investigations of moa kill sites left scientists aghast at the sheer quantity of the remains, and the area which they covered. Near the Rakaia rivermouth in 1869 Haast found an area of over ten hectares ‘covered with ovens, and moa and other midden bones, together with large numbers of flake knives of flint’. At some coastal sites the ploughing of the pioneers is said to have turned the fields white with bones. While the large kill sites of the eastern coast might represent several centuries of hunting, the general impression has still been that large numbers of moa were killed over a short space of time, with considerable waste of both flesh and bone.

What did moa meat taste like?

Moa flesh was surprisingly fatty, judging by the greasy residues of moa meals found in old ovens. It shared this quality with kiwi flesh, which is dark and was much favoured by the pioneers and pro-

spectors of last century. According to American ornithologists Austin Rand and Thomas Gilliard, ‘Cassowary flesh is prized and we found it dark, rich and tasty, quite unlike that of most birds.’ Sir Robert Falla thought roasted moa would have resembled roast ox. A nesting moa may well have been an especially attractive food source, assuming that the moa stored up fat reserves for the long incubation in the way that the male emu does. On the nest, two generations of moa were at risk, and it is highly likely that the moa was doomed as equally by nest robbing as it was by hunting. During the season most likely in early spring — moa nests would have been fairly easy to locate. Repeated year after year, nest robbing would soon lead to a whole generation of birds being lost in any one area, as large birds tend to adopt what biologists call the K strategy of small broods and long lives, especially if they have few predators. Opportunistic hunting of the remaining adult and juvenile moa might see the local extinction of these birds in no more than a century. In this manner it is not difficult to imagine relatively small numbers of people eliminating the moa and other ground-nesters over large areas. Although eggshell fragments are not commonly found with moa bones at archaeological sites, in 1865 at Puketoi in Central Otago, W. D. Murison saw a long line of old ovens, and in them an enormous quantity of eggshell fragments. Geologist Alexander Mackay said in 1905 that at one of his collecting spots near Wellington he had found ‘‘gallons’’ of eggshell fragments, which had plainly been cooked, and the contents doubtless eaten. A moa egg would have made a good meal. ‘As a rough guess, I may say that a common hat would have served as an egg-cup for it: what a loss to the breakfast table!’ exclaimed Walter Mantell, who could be considered New Zealand's first archaeologist for his excavations at Kaupokonui in 1847. But a moa egg was also a useful container and an item of trade. The moahunter burials uncovered on the Wairau Bar in the 1940s turned up 11 moa eggs that had been interred with other artefacts. Thus the eggs played a significant role in the simple economy of the early Maori, just as did the bones, when no longer green, and the bird’s skin and feathers.

Dog and rat

Although hunting and nest robbing might explain many local extinctions, the moa had also to contend with the dog and the rat. Whether the dog roamed wild is still in dispute. It is significant that kuri bones, though common in middens, are quite unknown from any natural deposit of animal bones in caves or elsewhere, and that the moa bones found in middens or ovens are only very rarely gnawed. From this latter observation Haast deduced that the moahunters did not have dogs, because the animals ‘would not have refrained from attacking the remains of their masters’ feasts’.

However, Hector remarked in 1872 that the wild dogs seen in the Otago interior in the 1850s were ‘not to be confounded with the true wild dogs of New Zealand, of which only a few specimens have been obtained, and always in dense bush as the district between the Mataura and Waikawa’. Archaeologist Atholl Anderson believes the southern Maori bred their kuri especially for hunting large birds, and cites the marked neck and jaw muscle development discernible in the remains of these southern dogs. Maori use of dogs for hunting kiwi and kakapo in the early days of European contact has been recorded in many accounts, and Heaphy noted in 1846 that the Maori of the upper Buller attributed the local extinction of the kakapo to wild dogs. It has been suggested that the kiore could also have affected moa, damaging their breeding success by harassing the birds on the nest. Kiore have actually been observed to kill nesting sea birds on an atoll in the Cook Islands, but the lack of other protein on the island has been put forward as the most likely cause. In New Zealand the kiore has been regarded as predominantly vege- tarian, with naturally a much wider choice of food than that on an infertile coral island. Nevertheless its presence on some offshore islands of New Zealand corresponds with a marked decline in numbers of large insects, seabirds and tuatara on these particular islands.

The fires of Tamatea

Other pressures on the moa developed with the arrival of the Polynesians. Soil horizons and pollen analyses have revealed that after Polynesian settlement, large areas of both islands, especially in Hawkes Bay, Marlborough, Canterbury, and Otago were set alight. Only a thousand years ago almost the whole of the country was in forest, or at least in scrubland. Even the swamps, then far more extensive, had their own cover of forest. Only alpine altitudes and those areas freshly disturbed by volcanic action appear to have been open country, apart from some persisting open areas in Central Otago, where charcoal from natural fires dates back to 6,000 BC. With these exceptions, permanent forest clearance began about one thousand years ago, with the most dramatic phase occurring about 1250 A.D. Even by that time however, as Atholl Anderson points out, the most intensive period of moa hunting was over, at least in southern New Zealand, suggesting that moa numbers were already signifiantly reduced. Although some very favourable habitats — vast tracts of rich podocarp forest — had been destroyed in these fires, it is also obvious that immense refuges of forest still remained on both islands, especially on the wetter western side of both islands. Yet moa disappeared from these unfired forests too. There is also a widespread Maori tradition that ‘the fires of Tamatea’ were chiefly responsible for the demise of the moa, although sources vary as to whether these fires were natural or induced, and as to their main purpose. A tradition recurrent in the South Island, noted in the 1840s and 1850s, was that the moa were child-steal-ers, and the fires were a revenge involving all the tribes.

The Progress of extinction The earliest Europeans to comment on the fate of the moa drew on Maori tradition and their own observations of the more populated North Island in suggesting that the bird had vanished there before disappearing from the South Island. The later exploration of the South Island by settlers and scientists confirmed this with the discovery of moa remains which seemed much fresher. In the North Island the moa first disappeared from the far north, and from coastal areas; then progressively south. The bird seems to have lingered longest in the deep interior bounded by the King Country, the Wanganui and Taupo regions, and in the endless forests of the Wairarapa. The evidence for this is, however, only fragmentary, and only the general course of extinction can be suggested. Within the South Island, the moa was first exterminated from the eastern seaboard, from Marlborough down to Southland, then from most of Nelson and the West Coast, and from Central Otago. Post-European archaeological finds in Fiordland support Maori traditions that this region was the moa’s last stronghold. Fiordland was also the final refuge for Maori tribes pushed south and west, by northern invaders. There was some memory amongst the Maori of the progress of extinction. On the Auckland isthmus a woman of the late 1600s, Rangihaumoa, was so named because the day of her birth coincided with the last nest of moa eggs to be found in that

area. In the nineteenth century it was common wisdom that the last moa in the northern North Island had lived on top of Whakapunake, a mountain on the East Coast. In the south of the South Island, Beattie found a number of traditions concerning the last known birds of different localities. He was told the last moa in northern Southland, for instance, was supposedly killed on the Waimea Plain by one Parawhenua, sometime around 1800, while the last refuge of all was said to be ‘in the area between Te Anau and Big Bay’, on the West Coast. The archaeological record shows that moa numbers were severely reduced over most of the country by 1500 A.D., and very few moa hunter sites have been dated to later than 1600 A.D. Scientists have differed widely in their estimates of the date of extinction of the moa, but obviously as the bird became rarer, the corresponding kill sites did too, and very little of their evidence is available. The succession of occupying tribes over the centuries — always descending from the north where the moa had already largely vanished is a reasonable explanation for the very minor place of the moa in tradition and legend, and in place names and proverbs. This surprising absence is best summarised in the later chapters of Roger Duff's The Moa Hunter period of Maori Culture, yet there is strong evidence traditional, archaeological and-historical that the moa was by no means extinct in the south of the South Island in the 1700s.

The extinction of the moa and other ground-dwelling birds is counter to prevailing attitudes that the Maori of old was a conservationist. Certainly this century the destructiveness of the Pakeha has been contrasted with the perceived care of the Maori for their lands and food resources. ‘The Maori was always careful to conserve his food supplies, and to prevent fires from injuring or destroying his food-reservoirs, the forests. He had his closed season, the rahui, when no bird might be taken; would he not have his rahui for the moa?’, asked the scholar J. C. Andersen. However, the clearance of the forests and the pre-European loss of 22 flightless bird species belies this image of their Polynesian ancestors. This is no special indictment of those people, but of human nature in general. In the story of New Zealand then, Maori supplanted moa, and valley by valley, forest by forest, the big birds gave up their ground until at last their furtherest refuges were penetrated. There, at a time almost certainly after 1800, the last meal was made of moa and egg. 9 Barney Brewster has taken up where he left Off in his ‘‘Moa’s Ark" article in the May 1986 Forest and Bird. This article is abridged from the second chapter of his book Te Moa: the life and death of a unique bird, to be published in October.