"They like the trees here, the fruit from the trees, so sometimes they are here," Supriatna says softly, as we trek through the natural beauty with midday light streaming through the foliage.
"This is keystone to the gibbons. You can't kill the trees" he continues emphatically, pointing out the dainty figs that are a staple part of the gibbons' diet.
But that's exactly what's going on. Indonesia has the shameful distinction of holding the "highest deforestation" title in the 2008 Guinness Book of World Records, destroying an estimated 300 soccer fields of forest every hour.