The Campbell Island Teal: history and review

Abstract

We dedicate this paper to Ronald Walter Balham, friend, teacher and important contributor to the history of Campbell Island Teal. A small flightless duck was collected from waters near Campbell Island in the New Zealand subantarctic in 1886 and remained unreported for 50 years. A second specimen was obtained in 1944 but it was not until 1975 that the existence of a tiny remnant population of Campbell Island Teal was confirmed on 23 ha Dent Island, an islet 3 km off Campbell Island's western shores. Formal descriptions of adult male and female, juvenile and duckling are given. Superficially, the species resembles two other teal from the New Zealand area, Brown Teal and Auckland Islands Teal, but is considerably smaller (mean male weight 371 g, female 301 g) and darker than either. On Dent Island the teal live terrestrially in a subantarctic tussock grassland and megaherb community wherein pairs appear to hold territories year-round in the damper sites. Neither nest, egg nor duckling has been seen in the wild but the breeding season is assumed to be November to January. The breeding component of the population is unlikely to exceed 25 pairs. To fuel the establishment of a second wild population, 15 birds are held in captivity (as at May 1996), resulting from the removal of seven males and four females from the wild population since 1984 and the raising of seven in captivity. Eradication of Norway Rats from Campbell Island is required before teal can be reestablished on what was probably their former stronghold.