Takahē

The South Island takahē (Porphyrio hochstetteri) is a flightless swamphen indigenous to New Zealand and the largest living member of the rail family. It is often known by the abbreviated name takahē, which it shares with the recently (14th century) extinct North Island takahē. The two takahē species are also known as notornis. Takahē were hunted extensively by both early European settlers and Māori, and takahē bones have been found in middens in the South Island. Fossil remains have also been found across the South Island. They were not named and described by Europeans until 1847, and then only from fossil bones. In 1850 a living bird was captured, and three more collected in the 19th cen...

The South Island takahē is a sedentary and flightless bird currently found in alpine grasslands habitats. It is territorial and remains in the grassland until the arrival of snow, when it descends to the forest or scrub. It eats grass, shoots, and insects, but predominantly leaves of Chionochloa tussocks and other alpine grass species. The South Island takahē can often be seen plucking a snow grass (Danthonia flavescens) stalk, taking it into one claw, and eating only the soft lower parts, which appears to be its favourite food, while the rest is discarded. A South Island takahē has been recorded feeding on a paradise duckling at Zealandia. Although this behaviour was previously unknown, the related Australasian swamphen or pūkeko occasionally feeds on eggs and nestlings of other birds as well.

New Zealand

The South Island takahē is a sedentary and flightless bird currently found in alpine grasslands habitats. It is territorial and remains in the grassland until the arrival of snow, when it descends to the forest or scrub. It eats grass, shoots, and insects, but predominantly leaves of Chionochloa tussocks and other alpine grass species. The South Island takahē can often be seen plucking a snow grass (Danthonia flavescens) stalk, taking it into one claw, and eating only the soft lower parts, which appears to be its favourite food, while the rest is discarded. A South Island takahē has been recorded feeding on a paradise duckling at Zealandia. Although this behaviour was previously unknown, the related Australasian swamphen or pūkeko occasionally feeds on eggs and nestlings of other birds as well.

The South Island takahē is monogamous, with pairs remaining together from 12 years to, probably, their entire lives. It builds a bulky nest under bushes and scrub, and lays one to three buff eggs. The chick survival rate is between 25% and 80%, depending on location.

The South Island takahē is the largest living member of the family Rallidae. Its overall length averages 63 cm (25 in) and its average weight is about 2.7 kg (6.0 lb) in males and 2.3 kg (5.1 lb) in females, ranging from 1.8–4.2 kg (4.0–9.3 lb). The lifespan of a takahē can range from 18 years in the wild or 22 in animal sanctuaries. Its standing height is around 50 cm (20 in). It is a stocky, powerful bird, with short strong legs and a massive bill which can deliver a painful bite to the unwary. Although a flightless bird, the takahē sometimes uses its reduced wings to help it clamber up slopes. South Island takahē plumage, beaks, and legs show typical gallinule colours. Adult takahē plumage is silky, iridescent, and mostly dark-blue or navy-blue on the head, neck, and underside, peacock blue on the wings. The back and inner wings are teal and green, becoming olive-green at the tail, which is white underneath. Takahē have a bright scarlet frontal shield and "carmine beaks marbled with shades of red". Their scarlet legs were described as "crayfish-red" by one of the early rediscoverers. Sexes are similar; the females are slightly smaller, and may display frayed tail feathers when nesting. Chicks are covered with jet-black fluffy down when hatched, and have very large brown legs, with a dark white-tipped bill. Immature takahē have a duller version of adult colouring, with a dark bill that turns red as they mature. South Island takahē are noisy. They have a non-directional warning womph call, which was described by the rediscoverers of takahē as someone "whistling to them over a .303 cartridge case", and a loud clowp call. The contact call is easily confused with that of the weka (Gallirallus australis), but is generally more resonant and deeper.

One of the original long-term goals was to establish a self-sustaining population of well over 500 South Island takahē. The population stood at 263 at the beginning of 2013. In 2016 the population rose to 306 takahē. In 2017 the population rose to 347—a 13 percent increase from the last year. In 2019, it increased to 418. As of 2023, the population is around 500.

The near extinction of the formerly widespread South Island takahē is due to a number of factors: over-hunting, loss of habitat and introduced predators have all played a part. The introduction of red deer (Cervus elaphus) represent a severe competition for food, while stoats (Mustela erminea) take a role as predators. The spread of the forests in post-glacial Pleistocene-Holocene has contributed to the reduction of habitat. Since the species is K-selected, i.e. is long-lived, reproduces slowly, takes several years to reach maturity, and had a large range that has drastically contracted in comparatively few generations, inbreeding depression is a significant problem. The recovery efforts are hampered especially by low fertility of the remaining birds. Genetic analyses have been employed to select captive breeding stock in an effort to preserve the maximum genetic diversity.

The third takahē collected went to the Königlich Zoologisches und Anthropologisch-Ethnographisches Museum in Dresden, and the Director Adolf Bernhard Meyer examined the skeleton while preparing his classification of the museum's birds, Abbildungen von Vogelskeletten (1879–1895). He decided the skeletal differences between the Fiordland bird and Owen's North Island specimen were sufficient to make it a separate species, which he called Notornis hochstetteri, after the Austrian geologist Ferdinand von Hochstetter. Over the second half of the 20th century, the two Notornis species were gradually relegated to subspecies: Notornis mantelli mantelli in the North Island, and Notornis mantelli hochstetteri in the South. They were then incorporated into the same genus as the closely related Australasian swamphen or pūkeko (Porphyrio porphyrio), becoming a subspecies of Porphyrio mantelli. Pūkeko are members of a widespread species of swamphen, but based on fossil evidence have only been in New Zealand for a few hundred years, arriving from Australia after the islands were first settled by Polynesians. A morphological and genetic study of living and extinct Porphyrio revealed that North and South Island takahē were, as originally proposed by Meyer, separate species. The North Island species (P. mantelli, as described by Owen) was known to Māori as moho; it is extinct and only known from skeletal remains and one possible specimen. Moho were taller and more slender than takahē, and share a common ancestor with living pūkeko. Although it was historically proposed that the two takahē species were unrelated, a genetic analysis published in 2024 suggested that they are each other's closest relatives and likely descended from a single ancestor that colonised New Zealand, with the split between the two species dated at around 4 to 1.5 million years ago.