Takahe in increasing danger of extinction

Press, 8 May 1978, Page 2

Takahe in increasing danger of extinction

The takahe, once thought to be extinct, now appears; to be in increasing danger of i becoming so. Surveys in! the Murchison mountains in Fiordland, the sole remaining haunt of the takahe, show that numbers have more than halved in the last 10 years. The sharpest decrease occurred in the late 19605, because of harsh weather and environmental extremes. The takahe is now thought to inhabit the area in numbers of only 200 to 250. In a two-day seminar at Te Anau to examine the possible future of the takahe, the three main environmental influences were listed as introduced red deer and stoats; quality of vegetation; and harsh weather. The takahe. which has an average life span of five to six years, is disadvantaged by a low reproductive rate. The average cluth is one to three eggs. About 80 per cent of pairs breed annually, with an estimated 70 per 'cent hatching success. But chick survival is usually extremely low. The highest mortality rate occurs in the chicks’ first three months. The reasons for this are not yet known, but studies to determine the effect of the quality of the surrounding vegetation will be made this year. Chicks are fed on insects by their parents during their first three to four weeks, and then introduced to plant material. Population studies by Mr J. A. Mills, a scientist in the

Wildlife Service, were outlined to the seminar, showling that takahe in the low ! alpine areas of the Murchison mountains have a “significantly higher” mortality rate than high alpine takahe, which generally appeared better nourished and were heavier in weight. The three areas covered in the 'study were the low-alpine Takahe Valley-Point Burn area, and the Eyles Valley anti Miller Peak, both highalpine areas in the west of the mountains. Takahe Va-ley-Point Burn, in the eastern Murchisons, is unique in that its valley floors are treeless and covered with red tussock, of a lower nutritive value than other tussock species in higher areas. In winter, the valley floors freeze over, severely hampering the takahe’s feeding. This is thought to be a

major cause of the extremely low survival rate of chicks in the area. A further sharp population decline occurred between 1967 and 1972, when deer began to compete for the takahe’s preferred tussocks, after eliminating their own more palatable species. Competition for the preferred tussocks presumably lowered the nutritional plane of the takahe, ultimately affecting adult survival and chick production. Takahe numbers increased slightly from 1972 to 1975, however, as the numbers of deer were reduced by Forest Service control and plant species preferred by deer again became plentiful. Deer shooting in the Murchison mountains should be maintained because of this, Mr Mills said, and preferably increased during the winter.