The South Island piopio was originally described in the genus Tanagra and subsequently classified by some authorities in the genus Turdus. For a long time the South Island piopio was considered conspecific with the North Island piopio that dwelt in New Zealand'sNorth Island as the piopio, but later they were recognised as two distinct species due to pronounced differences in external appearance and osteology. Based on their smaller size, the description of the Stephens Island piopio was sometimes thought to be based on juvenile birds, but is now considered to be valid. The assumption of a well-flying bird evolving into a distinct subspecies on the small island close to the mainland seems hard to believe, but Stephens Island must have held a population of many hundred birds in 1894, and the piopio was apparently a reluctant flyer, not usually being found on offshore islands.
Subspecies
Two subspecies are recognized:
†T. c. capensis - : Formerly found in the South Island
Stephens Island piopio - Fleming, JH, 1915: Formerly found on Stephens Island
Description
This medium-sized bird was mostly olive-brown in colouration, with rufous wings and tail, and a speckled breast. The Stephens Island piopio was much smaller than the nominate race. The South Island piopio was considered to be one of the bestsong birds native to New Zealand.
Behaviour and ecology
South Island piopios were omnivorous, and relatively unafraid of humans, as they have been recorded as taking scraps of food from campers. Lice of the genus Brueelia were found on the South Island piopio.
Status
The South Island piopio was once considered common in undergrowth forests of New Zealand's South Island, until 1863 when the population began to decline. The piopio continued to decline rapidly throughout the 1880s, mainly due to predation by cats and rats introduced to the island by humans, and some habitat destruction. By 1888 the bird was said to be the rarest in all of New Zealand, and by 1905 it was considered virtually extinct. The last confirmed specimen was shot at Oharu in 1902, although alleged sightings continued. For example, unconfirmed South Island piopio records exist from near Patea in 1923, between Gisborne and Wairoa on 7 May 1947, in Nelson district, January 1948, and on 17 December 1947, at Lake Hauroko. The last supposed sighting was in 1963.
Stephens Island subspecies
The Stephens Island population became extinct, apparently in 1897, due to predation by feral cats which had multiplied to number in the hundreds by that time. The last specimen was taken on January 7, 1897, and there were none left by the end of 1898. Only 12 specimens of the Stephens Island bird exist today:
Staatliches Museum Dresden 16657, 16658, 16659, 16660, 16661; five spirit specimens purchased from Walter Buller's collection, received in 1899,
