Familiar coastal birds are the black-backed gull (Larus dominicanus) and red-billed gull (Larus novaehollandiae), while in the South Island the black-billed gull (Larus bulleri), although an inland breeder, comes to coastal areas in considerable numbers. Of terns, the white-fronted tern (Sterna striata) is the common coastal species, but the larger, red-billed Caspian tern (Hydroprogne caspia) also has an extensive distribution; a third species, the black-fronted tern (Chlidonias albostriatus) is, like the black-billed gull, an inland species in the breeding season.

The Arctic skua (Stercorarius parasiticus), a regular summer visitor, may be seen offshore harrying white-fronted terns as they carry fish to the nesting colony.

In addition to the black shag and little shag, the pied shag (Phalacrocorax varius) is widely distributed in harbours and estuaries. The common coastal heron is the reef heron (Egretta sacra), although in recent years it has tended to be outnumbered by the Australian white-faced heron.

The gannet (Sula serrator) and spotted shag (Phalacrocorax punctatus) breed in colonies, the gannet on a plateau like that of Cape Kidnappers (q. v.), or a gentle slope, and the spotted shag on the precarious foothold of the small ledges on precipitous cliffs.

One species of penguin, although absent from the sub-Antarctic islands, is universally distributed on the mainland coast, and extends to the Chatham Islands: this is the small blue penguin (Eudyptula minor), a sedentary species, remaining close to the coast all through the year and returning to the nesting burrows each night. There are northern and southern subspecies within the region, and a third distinctive subspecies (the white-flippered penguin) on Banks Peninsula.

Large massed colonies of various crested penguins (Eudyptes) are formed on the Snares, Campbell, Antipodes, and Bounty Islands. In contrast, the yellow-eyed penguin (Megadyptes antipodes) and Fiordland crested penguin (Eudyptes pachyrhynchus pachyrhynchus) nest singly or in small groups in the cover provided by caves or crevices between rocks. These are amongst the various sea birds of sub-Antarctic affinities breeding in southern New Zealand, the range of the yellow-eyed penguin including southeastern Otago and Stewart Island, as well as the Auckland and Campbell Islands, and the Fiordland crested penguin ranging from South Westland to Stewart Island.

The petrels include, amongst numerous smaller forms, the diving petrels, storm petrels, shearwaters and whalebirds (or prions); also in this Order are the majestic albatrosses and mollymawks. The smaller petrels almost all breed in burrows and they return regularly at night to the breeding colonies situated mainly on secluded islands. The New Zealand sub-Antarctic is inhabited by a wide range of species, some exclusively sub-Antarctic, while others are extensively distributed in the New Zealand region. Other species again are limited in range to the warmer northern waters. The great albatrosses – wandering albatross (Diomedea exulans) and royal albatross (q.v.) (Diomedea epomophora) – are characteristic of the sub-Antarctic, the nest being a hollow mound on the tussock-clothed slopes of remote sub-Antarctic islands. Campbell Island is the main centre for the larger southern race of the royal albatross, while the northern race breeds on islands of the Chathams group; there is a small mainland colony of the latter race at Taiaroa Head, Otago Peninsula, where a few pairs nest each year. The slightly smaller albatrosses, commonly known as mollymawks, differ in having closely packed nesting colonies like those of the crested penguins. Each group of sub-Antarctic islands, including the Chathams, has one or more breeding species.

Also familiar on all the New Zealand sub-Antarctic islands is a group of shags – the “blue-eyed shags” – represented by a number of forms in the New Zealand region. This group is restricted to the sub-Antarctic round the Southern Ocean. Two members of the group occur on the coast of the mainland: the Stewart Island shag (Phalacrocorax chalconotus) in the south of the region from Stewart Island to Otago Harbour, and the king shag (Phalacrocorax carunculatus) in Cook Strait.

The spectacular, noisy colonies of sub-Antarctic birds – petrels, penguins, or shags – serve as food for the southern skua (Catharacta lonnbergi). This gull-like bird of predatory habits feeds largely on small petrels, which are killed at night as they arrive at the burrows, and on eggs or young obtained on the colonies. It is found on islands surrounding Stewart Island, and from the Chatham Islands to the southern sub-Antarctic.

by Evan Graham Turbott, M.SC., Director, Auckland Institute and Museum.

• A History of New Zealand Birds, Buller, W. L. (1873, 1888)
• supplement (1905)
• Checklist of New Zealand Birds, Ornithological Society of New Zealand Checklist Committee, Fleming, C. A., convenor (1953)
• New Zealand Birds, Oliver W. R. B. (1955)
• Field Guide to the Birds of New Zealand, Gibson, R. B., Falla, R. A., and Turbott, E. G. (1964)
• The Life History of New Zealand Birds, Stead, Edgar F. (1932).