Black stilt holding its own

Press, 1 June 1982, Page 21

Black stilt holding its own

There is still hope for the black stilt. A big effort to protect its nesting areas at Lake Tekapo from predators was made in 1981-82 by the Wildlife Service and the Royal Forest and Bird Protection Society. The outcome was 13 fledglings — the biggest increase in the black stilt population for five years. \ ... , • The black stilt, faces extinction within the next 20 years if man does not intervene. The introduction of cats, rats, stoats, and ferrets, plus the diversion of water supplies in the McKenzie Country for. hydro-power schemes, have all-substan-tially affected the environment of the birds, which have not adapted well .

In 1979, the plight of the black stilt had become so bad that a series of measures were taken to protect it Predator-proof wire-mesh fences were setup at Mailbox Inlet (1980) and at Micks Lagoon (1981), while in the 1981-82 summer the Wildlife Service trapped in the Godley and Tasman Valleys. The Wildlife Service also experimented with cross-fostering of chicks. Results from Mailbox Inlet have been very encouraging. Eight young flew off it, representing 60 per cent of the season’s total, and. a big increase on 1980-81 when only two flew off it. Four of the young were from one brood and reared by their

own parents; the others had been fostered. But the close of the 1981-82 season has left rescuers with a few headaches still. The main ones are how to prevent Lake Tekapo from flooding Mailbox Inlet during the nesting season, how to catch the cunning last few trap-shy predators around some nesting areas, and how to accommodate eggs safely in incubators during manipulation of nests. Dr Ray Pierce, of the Zoology Department at the University of Otago, believes the flooding of nests in the Mailbox Inlet enclosure could be avoided by encouraging the birds to nest at a higher level. Raising the

base level of the inlet and creating small streams and ponds on higher ground would force the black stilts to live there, where there are fewer chances of being flooded by the lake. Work has begun on this. He believes that if the high fledgling rates and high adult survival rates are maintained, the black stilt population should begin to increase over the next few years. In the 1980-81 and 1981-82 seasons, there were I’l and 13 fledglings respectively. But 1981-82 was the better season because no adult birds were known to have died during the nesting season; compared with two in 1980-81 while guarding chicks.