Kiwi search and rescue in Northland

Forest and Bird, Volume 14, Issue 3, 1 August 1982, Page 7

Kiwi search and rescue in Northland

THOUGH some of our native birds have adapted well to changing conditions, others have been unable to do so. The recent history of New Zealand wildlife has many examples where a decline in numbers of a species or diminution in range has been recognised late in the day. The authors of this article, Society members Michael Taylor and Kerry Walshe, who have been engaged in recent searches for kiwis in Northland, hold that there are no grounds for complacency over the future survival of the country’s national bird in the wild on the New Zealand mainland.

CONTINUED farm and forestry development and _ redevelopment are an inevitable fact of life in New Zealand, and though there is general recognition that this must have a profound influence on wildlife, the absence of detailed knowledge of the effects is alarming. Attempts to regulate the extent and timing of farming Operations to accommodate the interests of native birds are the exception rather than the rule. It is against this background that kiwi searches and transfers have been taking place for several years in Northland and Auckland. First to be involved were members of the Otorohanga Zoological Society, and an initiative by Barry Rowe led to:.the= formation: of an Auckland-based group which in the past three seasons has shifted more than 50 kiwis from areas where their habitat was being reduced and released them in permanent bush reserves which should offer the birds a safer future. Primary aim The primary aim is a simple one — to rescue kiwis which are otherwise probably going to die, since the land development usually means the cutting or crushing of bush and scrub followed a few weeks later by burning. The individual areas being cleared are mostly small (15 or 20 ha of a private farm is the typical scale), but the

cumulative effect is liable to be considerable, especially when as in recent years there have been Government subsidies available for the clearing and conversion to pasture of unproductive land. Northland, in_ particular, has experienced the effect of this policy, with the result that there are places where kiwis were formerly plentiful, but now are scarce and others where the birds appear to be in exceptionally high concentrations, probably because of their having been driven out of adjacent areas. This latter situation seems to exist at present on several properties near Dargaville and eastwards towards Whangarei, and concerned farmers in this part of the country took the initiative

of contacting the Otorohanga Zoological Society to see what could be done to minimise kiwi losses and if possible also to enable the birds to be transferred and re-established elsewhere. If an owner is prepared to grant access to his land, first to establish that kiwis are present and secondly to enable an attempt to be made to remove birds which are judged to be at risk, what is the next move? Since native birds are to be handled, the first requirement is the necessary permit from the Wildlife Service of the Department of Internal Affairs. The Auckland group- was granted this authority to enable operations by the Ornithological Society and

Forest and Bird members, with a further permit to allow the kiwis to be banded for subsequent recognition; in this instance an individually numbered metal leg band is fitted together with a coloured plastic band, the. purpose of which is to denote the site where the bird was released. Night captures Though a few kiwis have been found: in their burrows during daytime, nearly all have been caught in the open at night either by a small party of searchers locating and surrounding the kiwi or by one or two patient searchers tracking it by sound and making a quick dash by torch-light to secure the bird before it could take shelter in the undergrowth, for once hidden the kiwi may remain frozen for minutes on end. Calls are obviously a help in locating the birds and provide the first means of estimating the kiwi population of an area, though calls are infrequent and experience suggests that a property may contain as many as five times the number heard calling within a given 2- or 3-hour period. Once the bird is captured (and to catch one in three seen on a particular night is good going), it is put into a box, carefully checked, and tied shut, since kiwis with their strong legs and sharp claws would easily break out of a flimsy structure. It is then kept as quiet as possible for subsequent transfer and release into’ its new home. Actually the bird is handled once more, which is when the identifying bands are fitted. Opportunity is then taken to weigh the bird — a female brown kiwi may weigh as much as 3 kg — to take notes of its condition, and to measure the bill as an indication of the sex with the knowledge that ranges of 100 to 120 mm for adult males and

120 to 150 mm for females hardly overlap. Much kiwi terrain is hilly and there are numerous hazards like potholes, roots, and patches of swamp, so that even where it has been possible to learn ‘the territory, in daylight hunting for kiwis is a challenge to even the boldest members of the team. After an early phase in which there was little success it says much for the dedication of the group that members have persisted and that over the past two summers we have been able to meet all requests which have reached us from Northland farmers to relocate kiwis from these farms — a total of ten properties from which 56 birds were removed during a number of calls. Other threats There are other threats to kiwis besides destruction of their habitat. Uncontrolled dogs, trapping, and possible competition from the continuing spread of opossums, which can occupy kiwi burrows, are among the problems, and without resorting to off-shore islands we cannot be _ sure whether there are any really safe refuges for kiwis in the wild. One release site where 13 birds have so far been released is a fenced bush reserve at Tapora on the Okahukura Peninsula, Kaipara Harbour; the other is the Society’s Matuku Reserve in West Auckland (described in Forest and Bird, May 1979). Members living close to the reserve report hearing kiwi calls, and it is hoped that the birds may start to breed there. If these releases lead to kiwis becoming re-established in areas which they formerly occupied, an important subsidiary aim of the rescues and transfers will have been achieved.

The leaders of kiwi salvage operations, which is the official term for these rescue missions, will always be the first to admit that in an ideal world such steps ought not to be necessary. Indeed we should not have to wait for an ideal world; quite modest shifts in the balance of concern for the well being of nature could suffice to give the kiwi and other native wildlife a better deal and at a price which would not be large on the scale of modern economics. Meanwhile those who care continue to do what little they can. The Auckland kiwi rescue group has some 60 participants; young people are well represented, and children who have sometimes been taken along will have gained immensely from the educational experience. From 15 to 20 people travelling by car and operating over a weekend form a normal-sized team. Tents are sometimes used, but the farm woolshed is the usual base, and the group is particularly grateful for this _permission as well as for approval to search the land. City members of the group have gained a better appreciation of the problems of maintaining or expanding the production of a farm under today’s conditions and of the pressures which make it difficult for the farmer who wishes to retain bush or to allow regeneration of scrub on his property. The Society received a 1979 Mobil Environmental Award of $1,000 for kiwi rescue work which has been fully expended on travelling and equipment expenses of the project, and the group wishes to acknowledge this support as well as guidance from the Wildlife Service and the generous help and co-operation of farmers on whose property we have operated. =