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The Takahē or South Island
Takahē, Porphyrio hochstetteri is a flightless bird
indigenous to New
Zealand and belonging to the rail family. It was thought to be extinct
after the last four known specimens were taken in 1898. However,
after a carefully planned search effort the bird was rediscovered
by Geoffrey
Orbell near Lake
Te Anau in the Murchison Mountains, South Island, on November 20, 1948. The
specific scientific name commemorates the Austrian
geologist Ferdinand von
Hochstetter.
A related species, the North
Island Takahē (P. mantelli) or mōho is
extinct and only known from skeletal remains. Both forms were long
assumed to be subspecies of mantelli and were usually
placed in the genus
Notornis. However, it has been determined that the
differences between Porphyrio and Notornis were
insufficient for separating the latter, whereas the differences
between the North and South Island forms justifed the splitting
into two species as each evolved independently towards
flightlessness.
Description
The Takahē is the largest living member of the Rallidae; its
overall length is up to 63 cm (24.8 in) and its average
weight is about 2.75 kg (6 lbs), ranging from 1.8-4.2 kg
(4-9.2 lbs). It is a stocky bird, with reduced wings, strong legs
and a massive bill.
The adult Takahē is mainly purple-blue in colour, with a
greenish back and inner wings. It has a red frontal shield and
red-based pink bill. The legs are pink. Sexes are similar, the
females being slightly smaller, but young birds have mainly pale
brown plumage. This is a
noisy species with a loud clowp call.
Note large bill and frontal shield
Distribution and habitat
The species is still present in the location where it was
rediscovered in the Murchison Mountains. Small numbers have also
been successfully translocated to four predator-free offshore
islands, Tiritiri Matangi, Kapiti, Maud and Mana, where they can be viewed
by the public. Additionally, captive Takahē can be viewed at Te Anau and Mt Bruce wildlife centres. In June 2006 a
pair of Takahē were relocated to the Maungatautari Restoration
Project.
In total there were 225 remaining birds, but in July 2008, a
Department of Conservation worker shot one on Mana Island, after
mistaking it for a pukeko
during a cull.
Conservation
The near-extinction of the Takahē is due to a number of factors:
over-hunting, loss of habitat and introduced predators have all
played a part. Since the species 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.
Behaviour
The Takahē is found in alpine grasslands habitats. It eats
grass, shoots and insects. The Takahē can often be seen to pluck a
snow grass grass stalk, taking it into one claw and eating only the
soft lower parts which is a favorite food. The rest is
discarded.
Breeding
This species builds a bulky nest under bushes and scrub and lays
two buff eggs.
It is territorial. The chick survival rate is 73-97%.
Gallery
References
External
links