The Taru Jurug Zoo in Surakarta said orangutans Tori, 13, and Didik, 23, were moved Saturday to an island at the center of the zoo's lake to keep visitors from throwing lit cigarettes into their enclosure, The Jakarta Post reported Monday.
Zoo chief Lilik Kristianto said the orangutans would smoke any lit cigarettes thrown into the cage.
"At first they looked anxious and drained, but after two days they looked better and have started to play in the trees on the 300-square-meter (3,229-square-foot) area," Lilik said.
Daniek Hendarto, conservation program coordinator for the Jakarta Animal Aid Network's Center for Orangutan Protection said blood tests administered July 3 found Tori and Didik were both suffering from hepatitis and tuberculosis.
"We should focus on disciplining visitors. We have put up signs prohibiting visitors from throwing cigarettes into the apes' enclosure, but they keep doing it when nobody is looking. They think smoking orangutans are funny, hence they do it over and over again without knowing that the outcome could be fatal," Hendarto said.
He said the orangutans may remain on the island permanently to keep them away from cigarettes.