Land and freshwater birds
Land and freshwater birds on New Zealand's subantarctic islands are surprisingly numerous, diverse and in some cases very rare on this haven away from the mainland. No fewer than 15 species are found nowhere else on earth.
Uni colour parakeet - endemic to Antipodes Island
Some species of New Zealand birds have survived on New Zealand's subantarctic islands long after introduced predators wiped them out on the mainland.
For example the New Zealand snipe, extinct for around 1000 years on the mainland, thrive on The Snares, Antipodes Island and on some islands that have remained free of cats and pigs in the Auckland Island group. They also survived on Jaquemart, a small islet in the Campbell Island group, and are rapidly re-establishing on Campbell Island itself, now that rats have been removed.
Over the last 120 years many species of birds have been introduced to mainland New Zealand by humans and at least 10 species have successfully colonised one or more subantarctic island group including the redpoll, dunnock, blackbird and mallard.
The small teal of Auckland and Campbell islands are of great interest as they have independently evolved into flightless forms.
While flightless birds not particularly prevalent in New Zealand's subantarctic, several other forms, including the three snipe, the Auckland Island rail and The Snares fernbird, have reduced powers of flight.
The characteristic tameness of subantarctic land and freshwater birds, combined with their ground-nesting habit and unwillingness to fly, has made them vulnerable to introduced mammalian predators. This problem has been accentuated in some cases by the presence of introduced herbivores, which over the past 150 years have drastically altered the vegetation on some islands, reducing cover for many species.
The fact that some islands in each group have remained free of introduced predators has been vital for the survival of most endemic land and freshwater birds.
- Among the four endemic land birds of the Antipodes, is the Antipodes parakeet, which is the largest of the New Zealand parakeets at about 130g and 300mm long.
- The other three endemic species in the Antipodes are Reischek's parakeet (a subspecies of the mainland New Zealand red-crowned parakeet), Antipodes Island snipe and Antipodes Island pipit.
- Altogether 25 birds breed on the Antipodes group. Introduced birds include red poll, dunnock and starling.
- The Auckland Islands have the greatest diversity of native land birds, with more than 13 species, including the New Zealand falcon and the tui and bellbird.
- The Auckland Islands group also has its own snipe and teal together with an endemic rail, dotterel, tomtit and pipit.
Bounty and Snares Islands
- Three land birds are endemic to The Snares: the Snares Island fernbird, the Snares Island tomtit and the Snares Island snipe.
- The barren Bounty Islands and the Western Chain islets of The Snares are totally lacking in land birds.
The Snares Island snipe is endemic to the island
- The Campbell group boast three native land birds: the rare flightless Campbell Island teal, along with snipe and New Zealand pipit.
- Teal returned to Campbell Island – DOC returned the world's rarest duck to its home after 200 years absence through a 20 year internationally significant conservation project .
New Zealand's subantarctic islands would be a strong contender for the title of 'seabird capital of the world' with more than 40 seabird species, at least 11% of all the world's seabirds, breeding in the region and over 120 species having been observed at the islands or in the surrounding ocean.
Each year the urge to breed brings millions of seabirds to the islands. Because land masses are few and far between in the Southern Ocean, the subantarctic islands are vital breeding grounds for many of these birds. Most of them would not have touched land since the previous breeding season and the younger birds may not have been on land since they fledged up to seven years before.
The seabirds that breed on these islands range in size from delicate storm petrels, which will easily fit in your hand, to the great albatrosses, with wing-spans in excess of 3.3m.
Southern royal albatross, Enderby Island, Auckland Islands
The albatross and their small cousins the mollymawks are the most obvious and easily recognised of the seabids on New Zealand's subantarctic islands. Ten of the world's albatross species, some 40 percent, breed in the region, six of them nowhere else.
The six comprise three great albatrosses (Gibsons, Antipodean and southern royal) and three albatrosses in the mollymawk group (Campbell, Salvins and white-capped), although one white-capped nest has been found at the Chatham Islands.
Petrels, shearwaters, fulmars and prions
Among the world-wide family of petrels, shearwaters, fulmars and prions, 21 species or 30 percent breed on New Zealand's subantarctic islands.
Most of the petrels return to the islands after dark and leave before dawn to avoid the attention of predatory southern skuas.
The Southern giant petrel is the largest of the petrel species and is one of the earliest breeders on the Auckland and Campbell Islands, the single white egg being laid at the end of August. These birds superficially resemble the albatross and are aggressive predators and scavengers.
Sooty shearwaters, or titi, are the most numerous seabird in southern New Zealand waters. A vast population (millions of pairs) nest on The Snares. Having completed a 15,000km journey into the north Pacific these birds return with uncanny accuracy to the same burrow each year. Congregating offshore well before dark, they descend on their burrows in their thousands, forming one of nature’s great sights. At dawn they leave the islands like a black cloud, taking off from any suitable cliff top runway.
Although dependant on land during the breeding season, all of these birds rely on the sea for their food. When feeding chicks it is not unusual for adults to spend more than five days out at sea harvesting the food-rich waters which surround the islands.
New Zealand black-browed mollymawk on Campbell Island
Sooty shearwaters/titi are the most numerous seabird in southern New Zealand waters
Ten species of penguin have been recorded on New Zealand’s subantarctic islands. Four of these breed there. They include the yellow-eyed penguin, considered to be the world’s most endangered penguin, and three species of crested penguin, including the Snares crested and erect crested penguins who are both endemic to the region.
Yellow-eyed penguin are solitary nesters coming ashore in the late afternoon at their breeding sites on Auckland and Campbell islands. The crested penguins all form large colonies.
Penguin slope on Snares Island
Shags, gulls, skuas and terns
Each type of marine shag (cormorant) found in the area is endemic to its own island group, namely the Aucklands, Campbell and the Bounties, with the Bounty Island shag claiming a world record as the rarest of all cormorants with a population of fewer than 600 individuals.
Cormorants feed at sea but return to land each night to roost. They are present on the islands throughout the year.
Gulls, terns and skuas are present on all the islands of New Zealand's subantarctic, except the for the Bounties, where there are no skua. Species composition does, however, vary from island group to island group.
The southern skua is particularly widespread. On many of the islands the skua is the main predator, killing large numbers of petrels and taking penguin eggs and chicks.
Southern black-backed gulls are also widespread and while the red-billed gulls are absent from the Bounty and Antipodes islands they are present on the Snares, Aucklands and Campbell island groups.
Dainty Antarctic terns breed in small numbers on the island groups, and the larger white fronted tern is also found on the Auckland Islands.