Conservation of Bird Life Urgently Needed in Chatham Islands

Forest and Bird, Issue 185, 1 August 1972, Page 4

Conservation of Bird Life Urgently Needed in Chatham Islands

MAN'S apathy and thoughtlessness aided by lenient game laws have brought a serious threat to bird life in the Chatham Islands. A strong plea for the urgent conservation of bird species there is made in the following article.

THE archipelago known as the Chatham Islands is 538 miles east of Lyttelton and consists of two large islands (Chatham and Pitt) with about a dozen smaller islands and rocks. The first people to inhabit the group were the Polynesian Morioris, who established themselves about 1,000 years ago and remained almost undisturbed until the arrival of Europeans in 1791. The newcomers began sealing and whaling, which became important industries. In 1832 Maoris arrived from the North Island and they, with the European settlers, soon completely replaced the original colonisers. As the result of human occupation the indigenous plant and animal life of the islands has been drastically affected; more so, in fact, than that of any other major island or island group within the New Zealand biogeographical region. Since the beginning of European colonisation 50 percent of the land and freshwater-inhabiting birds of the Chathams either have become extinct or have been dangerously reduced in number. The New Zealand figures in comparison reveal the extent of the loss: North Island 25 percent, South Island 23 percent, Stewart Island 18 percent. What is additionally unfortunate is that the greatest loss has occurred among the endemic group (those found nowhere else), of which the Chathams has a high proportion; and it is disturbing to reflect that 73 percent of the endemic birds present when European colonisation began are now extinct, rare, or threatened. That similarly high losses were not experienced on the mainland probably reflects the more complete destruction of the Chatham Island habitat and the extreme vulnerability of'isolated island faunas to any modification of their environment.

By

G. E. Coster,

Wildlife Service, Department of Internal Affairs

Six Species of Birds in Danger There are now six species of birds peculiar to the Chathams which are very rare and threatened with extinction. They are: 1. The Chatham Island pigeon, now in very low numbers only on the two main islands. What remains of the bush habitat to which it clings is rapidly degenerating, and unless adequately protected reserves are established, there is little chance that it will survive for much longer. 2. The Chatham Island snipe, which has been confined to South East Island since the 1890 s, but was successfully reintroduced to Mangere Island in 1970 by the Wildlife Service. 3. The New Zealand shore plover, which has also been confined to South East Island since late last century, but was reintroduced to Mangere Island in March of this year by the Wildlife Service. 4. The Chatham Island petrel, which now breeds only on South East Island, where it is very rare. 5. The Chatham Island yellow-crowned parakeet, which has a total population of no more than 100 birds on Little Mangere. However, with the reservation of neighbouring Big Mangere and the removal of sheep to allow the vegetation to regenerate, its numbers are gradually increasing . there. . .. - 6. The Chatham Island black « robin, which is one' - of-The- world’s- rarest -birds.- - Its‘“total-

world population of 25-35 pairs is confined to Little Mangere. When consideration is given to the reasons behind the general decline in the bird life of the Chathams, it is difficult to lay the blame anywhere else but at the doorstep of man and his camp followers. Of the latter, the Polynesian rat, or kiore, which arrived in the canoes of the Polynesian settlers, has now apparently gone. Though usually regarded as fairly harmless, this rat does prey on birds, their eggs, and young and may well have contributed to the 20-odd extinctions thought to have occurred during Polynesian occupation.

In the wake of European settlement came farm animals (now present in both domestic and feral states on the main island and Pitt Island), the Australian brush-tailed possum, cats, European rats (two species), goats, pigs, hedgehogs, and mice. No rabbits or deer are established. The damage mammalian predators can inflict on an island’s bird life may be seen in a comparison of the histories of South East and Mangere Islands, the only two biological reserves so far established on the Chathams. Both have suffered extensive modification by fire, wind, and stock over a similar period and about the turn of the century both were frequented by commercial bird collectors; yet, whereas the former has lost none of its indigenous species, the latter, which at one time had cats, lost 12. Reserves of Great Value These reserves are now of great value to bird life. South East Island is a breeding ground for hundreds of thousands of petrels and other sea birds and provides the only fairly large bush area in the Chathams free from introduced mammals. In addition to the three very rare species inhabiting South East Island, mentioned above, the Chatham Island tui, red-crowned parakeet, and tit are plentiful there, but not elsewhere. Mangere Island, which shares a history of farming with South East Island, is an exceedingly valuable breeding ground for sea birds.

It was bought by the Crown in 1966 with money provided by the Royal Forest and Bird Protection Society and two Government departments. After the removal of sheep by the Wildlife Service in 1968, it is now free from all introduced mammals, and native bush is already regenerating vigorously. Since cats disappeared from the island in about 1950, it has been recolonised by the two endemic parakeets, white-faced storm petrels, and the Chatham Island snipe, which was reintroduced in 1970. These species had all been lost from the island when cats were present. Most other species are increasing in numbers. Little Mangere Island, which is usually considered along with Mangere Island, is steep, cliff-bound, and rises about 600 ft above sea level. It is extremely difficult of access and its 10 acres of scrub are unique as the final refuge of the Chatham Island black robin and Chatham Island yellow-crowned parakeet. There are no mammals present. Though the acquisition and reservation of this island are most desirable, the Maori owners have made it an essential requirement of sale that they be granted muttonbirding rights over Little Mangere Island. But there are objections to this. The southern muttonbird (sooty shearwater) may be hunted or killed (in accordance with the Third Schedule of the Wildlife Act 1953) only with Ministerial approval. Harvesting is permitted only on certain islands off the coast of Stewart Island, but elsewhere, including the Chathams, it is protected. Furthermore, unlike the islands off Stewart Island, which support vast numbers of these shearwaters, only relatively small numbers occur at the Chathams.' The Wildlife Service opposes the granting of muttonbird rights at the Chathams for several reasons, including the added fire risk involved and the increased danger of rats getting ashore. Such concern is not misplaced. Illegal muttonbirding generally takes place each March and April, and on a very recent trip to South East Island one party lit several fires to melt wax used to assist in removing down from the carcasses. An accidental fire at this critical stage of revegetation would, of course, be disastrous. On an earlier occasion muttonbTders on Little Mangere Island considerably damaged the low. dense scrub cover and the high density of petrel burrows. Dis-

turbance of this nature on Little Mangere’s small wooded caps could well start ecological changes intolerable to the robin and parakeet.

Greedy Exploitation Since the start of the European era men have greedily exploited the natural resources of the Chathams with almost no consideration for the principles of conservation. Perhaps the remoteness of the locality beguiled them into thinking that the status quo would remain for ever unaltered. Whatever the reasons, as a result today there is a vital need in the group for conservation of all natural resources and particularly of the depleted wildlife. The establishment of biological reserves is urgent and essential on the two main islands, but before these requirements can be realised the co-operation and good will of the islanders must be obtained; this is not simplified by the fact that most of them have no knowledge or understanding of conservation matters, a situation the Wildlife Service is trying to rectify. The game laws of the Chathams have perhaps contributed, to the present position. These laws, which are very liberal compared with those of New Zealand, have been enjoyed by the islanders for many years and impose a minimum of restraint on shooters. A licence is not required and no fees are payable. Duck and pukeko may be hunted from 1 May to 31 July, inclusive. Black swan and weka may be hunted at any time and swan eggs collected. Wildlife Held Cheaply Regrettably, this freedom has resulted ,in the wildlife of the Chathams being held cheaply. The indifference of some Chatham Islanders to the consequences of such behaviour is probably best illustrated by their treatment of the totally protected northern or Chatham Island ’ alba* tross. This magnificent bird, one of the least common of the world’s great albatrosses, breeds on The Sisters and Forty Fours, ' islands off the. Chathams, and elsewhere only on Otago Peninsula. A single egg is laid every second year. . , ' That exploitation in any , form would ultimately prove fatal to this species is selfevident from these facts. And yet it is well known that large numbers of albatrosses are falling prey to modern, freezer-equipped fishing boats working off the Chathams. A total of 80

birds was reported to have been taken recently by one boat on a single visit and a 3-ton truck load by another. To add insult to injury, it is the boast of many Chatham Islanders that

“illegal tegals” (their phrase for the slaughtered albatrosses) have been served to all visiting dignitaries over recent years (no doubt unbeknown to some). It is to be hoped that the nickname does not become an epitaph. In the last analyses it is up to the people who have made this island group their home to reverse a trend which in the long run will bring no advantages but only recriminations. No other area in the New Zealand region more urgently needs conservation — and none has been more neglected. The isolation of these islands is no longer a guarantee of immunity against change; nor can it serve as the sole measure of conservation. Already the Chatham Islands provide an outstanding example of how indifferent man can be to the consequences of his own destructiveness; and if anything is to be salvaged from the mess, it will be at the cost of considerable effort and sacrifice.

Annual Meeting Held at Dunedin

THE annual meeting in Dunedin attracted 70 members, the same number as at Wellington last year. The Sanderson Memorial Address attracted a similar attendance. Matters of particular importance discussed were: Beech Forests. There was a call for a firm stand by the Society against clear felling of beech forests and for substantial diminution in the cutting of all indigenous forests. Manapouri. A Press statement was released defining the Society’s concern at the mud flats likely to occur at Lake Te Anau and to the damage likely from any precipitate raising of the levels of that lake. Jubilee. A vigorous programme for the Jubilee was approved in outline and left to the executive to put into effect. Noxious Animals. A strong resolution on noxious animals was carried. It read as follows: “This Council is adamant in its opinion that in the interests of the great majority of New Zealanders there should be no relaxation of the provisions of the Noxious Animals Act and that no effort be snared to devise means to reduce as far as possible all noxious animals, with extermination remaining the ultimate goal.

Also to institute thorough research into the opossum menace and steps taken to deal with it.” Tautuku Lodge Visit Councillors staying in Dunedin on the Sunday had an enjoyable day excursion to Tautuku Lodge, on the Lenz reserve. In the bright sunshine of the day Tautuku Bay made a strikingly beautiful picture, and the well-kept and comfortable lodge with accommodation for up to eight was favourably commented on. Election of Officers Officers elected were: President. Mr R. C. Nelson: deputy president, Dr J. T. Salmon; treasurer, Mr A. K. Brown; executive, Messrs J. Jerram and C. W. Sievwright (Auckland), A. A. Pascoe (Palmerston North), N. E. Dalmer (Levin), F. E. B. Schlup, R. Slack, and H. D. Saunders (Wellington), Dr G. W. Ramsay (Nelson), Messrs J. W. Ramsay (Dunedin), and L. E. Henderson (Invercargill). Rule 9 Councillors elected were Messrs R. O’Regan and B. Teague.