Conservation of Marine Birds in New Zealand 



by 



Gordon R. Williams 



New Zealand Wildlife Service 



Department of Internal Affairs 



Wellington, New Zealand 



Abstract 



Marine species (pelagic birds and those of exposed coasts) make up about 48% 

 of New Zealand's native avifauna, excluding stragglers and antarctic species. 

 The biological history that has led to the present status of marine birds in this 

 archipelago of some 700 islands is outlined, methods of conservation are briefly 

 described, and some illustrative case histories of management programs are 

 given. In spite of the major environmental changes that have occurred in New 

 Zealand during 200 years of European occupation, only one marine species has 

 become extinct, although five such endemic species are currently regarded as 

 threatened as are a few subspecies of widely distributed forms. 



New Zealand, which lies some 2,000 km 

 southeast of Australia, has been a changing 

 archipelago for many millions of years. It has 

 been separated from any major landmass 

 (first, Gondwanaland and later, Australia) for 

 at least 80 million years. 



Before the arrival of man, probably between 

 1,000 and 1,500 years ago, New Zealand was 

 free of any land mammals except two species 

 of bats, and there were few avian predators. 

 These, among a number of other biological 

 peculiarities, reflect the archipelago's con- 

 siderable and long-standing isolation. 



There are nearly 700 islands 0.5 ha or more 

 in area in the New Zealand region; and, if 

 North, South, and Stewart islands are re- 

 garded collectively as the mainland, about 

 650 of these islands lie within 50 km of the 

 coast and 30 beyond that limit, to about 

 850km offshore (Atkinson and Bell 1973). 

 The archipelago extends from about 30 to 

 52 S lat. (over a distance of about 2,400 km) 

 that is, from the subtropical to the sub- 

 Antarctic and from about 166 to 176W 

 long. (Fig. 1). 



Pelagic and coastal birds must obviously be 

 an important part of the avifauna and, in fact, 

 aside from stragglers, antarctic species, and 

 established introduced species, they make up 



about 48% of the 173 in the New Zealand 

 Checklist (Kinsky 1970). Of the 83 species I 

 have regarded as marine, 48 (28%) are pelagic 

 and 35 (20%) shorebirds of exposed coasts. 

 Ten of the 48 pelagics (21%) and 12 (34%) of 

 the 35 shorebirds are endemic. 



More than a thousand years of occupation 

 by Polynesian man with his commensal Poly- 

 nesian rats (Rattus exulans) and a peculiar 

 breed of domesticated and feral dog (now ex- 

 tinct), did little damage to pelagic and open 

 coast species, even though many, if not most, 

 were used as food especially the petrels, and 

 particularly those belonging to the genera 

 Puffinus, Procellaria, and Pterodroma. How- 

 ever, the Europeans, who arrived about 200 

 years ago, brought with them a menagerie of 

 mammals and birds, and 33 species of each 

 have become established and are now feral 

 (Gibb and Flux 1973; Williams 1973). They 

 also put into practice, on a large scale, Euro- 

 pean methods of land use that had unfortu- 

 nate effects on almost the entire native avi- 

 fauna. Although terrestrial, freshwater, and 

 estuarine species suffered most, marine 

 species suffered also. However, reduction in 

 numbers and range rather than extinction 

 was the rule, except locally. 



Apart from habitat destruction by man and 



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