A helicopter carrying 19 rock ptarmigans left a zoo bound for the Central Alps on Wednesday in the first attempt to return the extinction-threatened alpine bird to the wild in Japan.
Nasu Animal Kingdom in Tochigi Prefecture, where the ptarmigans have been bred and raised, said the birds were headed for the 2,956-meter Mount Komagatake in Nagano Prefecture, the highest peak in the Central Alps and part of the mountain range known as the Japanese Alps.
According to Shinshu University, the wild ptarmigan population in Japan was estimated to be about 3,000 in the 1980s, but declined to less than 2,000 in the 2000s.