This EBA encompasses the Southern Alps and Fiordland of New Zealand's South Island, reaching 3,754 m on Mt Cook and including the upper reaches of eastward-flowing rivers such as the Rakaia and Waitaki. The 1,000 m contour is used to define the eastern boundary of the EBA because most restricted-range birds are thus confined. Offshore islands are also included as they are important refuges for many native birds.

The characteristic vegetation is forest: southern beech Nothofagus predominates, with podocarp or mixed forest in some areas including extensive lowland tracts. At higher altitude true forest gives way to a narrow belt of subalpine forest, and ultimately to various scrub and shrub communities, through to tussock grassland.

Distributions within this EBA vary. Nestor notabilis, Xenicus gilviventris and Mohoua ochrocephala largely occur throughout Fiordland and the Southern Alps, although M. ochrocephala has declined considerably in the last 20 years. Apteryx haastii is widespread only in north-west Nelson, the Paparoa Range and near Arthur's Pass in the Southern Alps. Porphyrio mantelli survives in the Murchison and Stuart mountains of Fiordland, and has an introduced population on the offshore island of Maud. Anarhynchus frontalis breeds on some 10 major river systems in Canterbury and northern Otago. Xenicus lyalli was discovered on Stephens Island in 1894, but became extinct shortly thereafter.

Two further species are confined to or have important breeding populations in this EBA, but are judged to have had historical ranges greater than 50,000 km²: Black Stilt Himantopus novaezelandiae today breeds in the upper Waitaki valley only; Kakapo Strigops habroptilus survives within this EBA (following introduction) only on Maud Island.

All the restricted-range species are considered threatened or Near Threatened, owing largely to introduced predators and competitors. Porphyrio mantelli has declined through competition for food from red deer Cervus elaphus and predation by stoats Mustela erminea. Apteryx haastii is declining in some areas owing to predation by introduced mammals (possums, mustelids, cats and dogs). Mohoua ochro- cephala has periodic population crashes in response to the stoat irruptions that follow major beech-mast production and subsequent mice plagues; it has disappeared from some of the best habitat in northern South Island, perhaps because of introduced wasps which compete for 'honey dew' (an important food source in beech forest). Anarhynchus frontalis is subject to predation by stoats and cats, but also suffers from a decline in the quality of nesting habitat owing to encroachment of weeds as hydroelectric schemes reduce seasonal flooding of riverbeds.

The many other threatened landbirds in this EBA were historically widespread, although many have very restricted ranges today. They include Brown Kiwi Apteryx australis (Vulnerable; the race australis which occurs in Fiordland and on Stewart Island is treated as a full species by Baker et al. 1995, Little Spotted Kiwi A. owenii (Vulnerable; only Long Island in this EBA), Australasian Bittern Botaurus poiciloptilus (Endangered), Blue Duck Hymenolaimus malacorhynchus (Vulnerable), Himantopus novaezelandiae (Critical; see 'Restricted-range species', above), New Zealand Kaka Nestor meridionalis (Vulnerable) and Strigops habroptilus (Extinct in the Wild; see above).

Several threatened seabirds are largely endemic to this EBA when breeding, including Hutton's Shearwater Puffinus huttoni (Endangered; Kaikoura Range), Fiordland Penguin Eudyptes pachyrhynchus (Vulnerable), Westland Petrel Procellaria westlandica (Vulnerable), New Zealand King Shag Phalacrocorax carunculatus (Vulnerable; stacks in the Marlborough Sounds) and Black-fronted Tern Chlidonias albostriatus (Vulnerable).

There has been much conservation action within this EBA (see, e.g., Lambert and Moritz 1995) and c.40-50% of the total area lies within protected areas, notably Fiordland and Kahurangi national parks. Major conservation programmes involving captive breeding and release, introductions and predator control are targeted at Porphyrio mantelli, Himantopus novaezealandiae and Strigops habroptilus (e.g. Clout and Craig 1995). There is growing concern, however, about the fragmentation of habitat and the impact of this on small relict populations with little or no gene flow between them. Increased tourism is expected to act to the detriment of surviving wild areas, and consequently there is a need to balance the desire for people to enjoy wildlife with the need to protect vulnerable species from excessive disturbance (D. Cunningham in litt. 1995).

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: South Island of New Zealand. Downloaded from https://datazone.birdlife.org/eba/factsheet/207 on 23/11/2024.