This story appears in the November 2016 issue of National Geographic magazine.

PANUT HADISISWOYO Conservationist

Orangutans that live in Sumatra usually make their nests in palm forests. But one day in 2014, Panut Hadisiswoyo caught sight of an orangutan riding around the streets of Medan, the island’s largest city, in a rickshaw. Hadisiswoyo runs the Orangutan Information Centre, an Indonesian NGO devoted to saving endangered apes, and so he gave chase, on foot, through traffic. “I jumped in the rickshaw and made the driver stop,” he says. Then he put the orangutan’s chaperone, a wildlife trader, under citizen’s arrest and called for backup from his staff. The police arrived three hours later.

His work is not often that exciting. It’s also rarely easy. The National Geographic emerging explorer spends most of his time trying to stop deforestation by palm oil and other commodity companies in the Leuser ecosystem, one of Asia’s largest lowland rain forests. He has worked with drone photographers to identify sensitive areas to protect, not only for orangutans but also for rhinos and tigers.