Story: Large forest birds
Page 3 – Takahē
The South Island takahē, a large flightless rail, hit headlines in the late 1940s. Takahē were thought to be extinct – but then, in 1948, Geoffrey Orbell rediscovered the South Island species (Porphyrio hochstetteri) in Fiordland’s Murchison Mountains. However, the North Island takahē (Porphyrio mantelli) is extinct.
South Island takahē
Weighing up to 4 kilograms and 63 centimetres long, the South Island takahē is the world’s largest rail. Several million years ago its ancestors flew from Australia to New Zealand, where, without ground predators, the takahē became flightless. This colourful bird has turquoise, purple, brown-green and navy plumage, with a white undertail and bright orange-red bill and legs. Today South Island takahē remain in the Fiordland mountains, and have been introduced to several island sanctuaries.
North Island takahē
The ancestors of the taller but slighter North Island species arrived in New Zealand more recently than those of the South Island bird. The North Island takahē was last seen in the late 19th century, in the Tararua Range.
Both takahē species are related to the pūkeko (Porphyrio melanotus), which came to New Zealand from Australia just hundreds of years ago, and can still fly.
New Zealand once had up to nine endemic flightless rails. The South Island takahē and the weka are the only two to survive human colonisation.
Habitat and feeding
The remnant takahē population in Fiordland feed on snow tussock shoots in summer. In winter they retreat to nearby forest, where they eat fern rhizomes. People assumed this harsh environment at 1,100–1,400 metres altitude was the takahē’s preferred habitat. But to survive on the low-nutrient foods there, it has to eat continuously for up to 19 hours a day, and must withstand snow and alpine temperatures.
It is now understood that the alpine environment is the takahē’s last refuge – the conditions were harsh enough to limit numbers of introduced predators and competitors. Takahē bone remains show that, until recently, they mostly occupied the edges of dense shrublands and dry forests around lowland swamps and rivers, from Canterbury to Southland. But the surviving birds have probably been in the high country long enough to adapt to subalpine conditions.
A takahē female lays one to three off-white eggs between October and December, often while snow still lies on the ground. The male and female take turns incubating the eggs for a month. Juveniles can breed in their first year, but often remain with their parents for up to two years, and even help them raise chicks. Takahē guard their breeding territories fiercely.
Takahē – lost and found
Māori hunted the takahē, which made a good-sized meal. By the 1840s it was considered rare. Between 1850 and 1898 four birds were killed and mounted as museum specimens, but after that the trail ran cold, despite reported sightings in the Fiordland wilderness.
In 1949 an 80-year-old man who had eaten a takahē remarked that it was good eating but ‘all drumstick’. 1 Each leg and thigh of a takahē contains five times more meat than the breast.
As a young man, Geoffrey Orbell had been intrigued by the stories of the ‘lost bird’. He roamed Fiordland and thought takahē might be found near Te Wai-o-pani, an alpine lake now known as Lake Orbell. On 20 November 1948 he and three companions finally discovered the elusive bird. Once abundant throughout the South Island, its numbers had plummeted to just a few hundred.
Race to save the bird
In 1982 the Fiordland takahē population was estimated at 121 – a 40% decline in a decade. This coincided with the rapid spread of feral deer, which damage the tussock grasses that takahē eat. So scientists launched a conservation programme which saw the number of wild Fiordland takahē rise to 171 by 2005. It involved:
- controlling deer
- protecting the takahē from predators, especially stoats
- raising chicks in captivity for release in the wild
- establishing other populations on islands.
Takahē were placed on Kapiti Island, near Wellington, in 1980, in case the mainland population became extinct. The move was a gamble, as some believed they would not survive on a diet of introduced grasses. But the birds have survived and bred – although some eggs are infertile, possibly because of young birds breeding, inbreeding, or the sudden change of environment and social structure.
By 2006 there were 96 takahē on Maud, Mana, Kapiti and Tiritiri Matangi islands.