Fifteen-year-old Tori picked up smoking 10 years ago after visitors threw cigarettes into her enclosure at the zoo in Surakarta, also called Solo city.

"She was sent to the private island so that smoking zoo visitors won't be able to throw cigarettes at her," zoo director Lilik Kristianto said.

Tori shares her new home, a small island with five trees in the middle of a lake in the zoo's compound, with her 16-year-old boyfriend, Didik, Kristianto said.

They would stay there permanently, he said.

There are about 6 000 Sumatran orangutans in the wild.

Indonesia, home to 242 million people, ranks third in the world for the number of smokers after China and India, according to the World Health Organisation.

Thirty-four per cent of Indonesian adults smoke with many starting the habit at an early age, a 2010 Health Ministry report showed.

Meanwhile, the Sumatran Orangutan Conservation Programme transported three orangutans for release into the wild within a conservation forest in Aceh province Wednesday from its quarantine centre in North Sumatra.

The programme is a collaboration among organisations that include the PanEco Foundation, the Indonesian government and the Frankfurt Zoological Society.