SUKABUMI: Tini Kasmawati uses a crude pulley system to raise a bucket of bananas into the canopy of an Indonesian rainforest. Within minutes, a silvery gibbon, a baby clinging to its chest, swings through the trees and grabs a few.

For nearly eight years, Tini, 49, has been on a self-funded mission to care for the endangered animals, which are native to the jungles of West Java, spending at least two hours a day with them.

Also known as the "Javan gibbon" or "owa jawa" locally, populations of the silver-haired primates are declining because of illegal animal trafficking and deforestation. Only about 4,000 remain in the wild, according to Conservation International, and about 24 in this area, according to a local wildlife conservation group.

When Tini met a Dutch student, who travelled to the tropical country to study gibbons in 2014, she felt ashamed of her own ignorance. That spurred her to care for at least six of the creatures, which she has come to regard as family.

"It's an honour that I'm able to do this, not many people out there want to or can do this," Tini said in an interview.

Animal welfare activist Budiharto, who runs Cikananga Wildlife Centre, which monitors endangered species in West Java province, said Tini's work has made little difference to gibbon populations, but she has helped provide much needed food for the primates.

There are plans to convert Lengkong forest into a protected area, but the fate of these scrunch-faced monkeys remains precarious as they are plagued by inbreeding, Budiharto said.

Tini hopes her work can help conserve the remaining gibbons and allow researchers to educate the public about them.

"If God is willing, as long as I can still walk, I will not stop,” she said.