Takahe numbers up for second year

Press, 28 January 1986, Page 17

Takahe numbers up for second year

By

TESSA WARD

Takahe, the rare, flightless, and timid birds thought to have been extinct 34 years ago, have increased in numbers in Fiordland’s Murchison Mountains for the second year in succession. Delighted wildlife officers counted 181 adult takahe (Notornis Lochstetter 1) at the end of the last breeding season, which began in late October and ended in late December.

The previous breeding season tally was 153 adult birds. That was the first time an increase had been recorded after three years of totals around 120 adult birds.

An officer for protected fauna in the Wildlife Service at Te Anau, Dave Crouchley, says that a rare bird species is considered to have reached “safe” numbers when its population is 500. “We really don’t know how long it will take for the takahe to breed up to that figure because this is dependent on several factors. An encouraging sign that the Fiordland takahe numbers could soon be complemented by more takahe at Maude Island, in Pelorus Sound, is recent mating behaviour of the young birds i there. “These nine takahe, moved rm Fiordland, weft too young breed during the l last season but will be quite capable in the

coming season.” Several factors are responsible for the increased takahe tallies over the last two breeding seasons, Mr Crouchley says. “Our techniques of managing the Fiordland takahe habitat and egg numbers are becoming more effective. The most important of these would be the deer control programme, hfigun in the early 19705, ensuring-a general recovery of the vegetation.

“During the last three breeding seasons we have been carrying out egg manipulation work using some of the principles adopted for management of the black stilt and back robin populations. The aim of this work is to find out the fate of all the eggs produced and to move eggs between nests so that each breeding pair of takahe»has one fertile and alive egg to hatch.” To check for fertility and life

inside an egg the wildlife staff place the eggs under a light and weigh them. “The point of leaving the takahe pairs with one egg only is to increase the chick’s chances of survival. Each breeding pair is able more easily to protect a chick from bad weather if it doesn’t have other eggs in the nest to incubate. “This egg movement programme has allowed us to use surplus eggs for our three-year-old artificial rearing programme. For the first time we reared chicks last season in a new rearing reserve at Gorge Hill, just out of Te Anau.” These artifically bred birds will provide a reserve stock for future releases into Fiordland other than in the Murchison Mountains region.

“To make sure the reserve reared birds are capable of surviving back in the open environment we are developing a learning programme for them, including puppet models of their parents and tape recordings of takahe calls. The Maude Island takahe serve as another prang to our attack for aiding survwal of the species.

“These takahe should show us whether the species is capable of

surviving well on pastoral grasses and clover as opposed to the tussock lands of Fiordland.” An on-going research project to find out if improving the nutrient value of the tussock boosts the chances of takahe survival has not produced conclusive results yet, Mr Crouchley says. Fiordland winters with heavy chronic snowfalls can cause star-

vation among the takahe. “Some of the takahe try to survive in tussock tunnels under the snow while others are forced to head for the forested valleys where they feed largely on fern roots and insects,” says Mr Crouchley. “This is one of the reasons why effective deer control is so important to the survival of the takahe.” A proposed deer control programme for Fiordland’s Stuart Mountains, where the Wildlife Service would like to introduce some of the reserve stock of takahe, has met adamant opposition from the New Zealand Deerstalkers’ Association. So far parties concerned are at staled mate over the issue after a

November meeting at Te Anau. The association maintains the reduction of deer numbers in the Murchison Mountains area has had little effect on takahe numbers.

“The move to release juvenile birds reared in captivity into the Stuart Mountains area is in direct conflict with Wildlife Service scientists’ conclusions on takahe management,” the assoication’s president, Mr John Bamford says. “Juvenile takahe require some education from their parents in foraging and survival in the wild,” he adds. The New Zealand Recreational Hunting Council’s scientific advisor, Dr lan Henderson, has suggested an alternative area for releasing the juvenile takahe, around the Doon and Wapiti Lake area. The association challenges the efficacy of past and present takahe management, claiming that takahe numbers have declined from about 500 adult birds in 1967 to the low figures of 1983. In reply, Mr Crouchley says that it was not until the 1970 s that accurate tallies of adult takahe were taken. “We are sceptical about the 1960 s figures put forward of around 500 takahe and suspect the total was more like 300 birds.”