We watched in silence as the two orangutans, a mother and her child, prepared themselves for an encroaching rainstorm.
While the air grew thicker, the mother — whom the local guides had nicknamed Minah — led her child toward the canopy and into a nest she had built earlier that day. Then, collecting vines and leaves, she wove an umbrella out of the foliage and held it devotedly over her daughter.
Thunder shook the ground, spooking a pair of giant hornbills, who honked indignantly. The haunting call of gibbons echoed across the canopy.
Its 6 million acres of dense rainforest is home to 389 species of birds and 130 species of mammals, including the world’s largest wild population of Sumatran orangutans.
Though they once thrived in healthy jungles from Indonesia to China, wild orangutans, which are among the rarest and the most intelligent of the great apes, are now limited to the rain forests of two Southeast Asian islands: Borneo and Sumatra. Mainly because of habitat destruction — in the form of mining, logging and the highly destructive practices of the palm oil industry — their populations have dwindled.
The Bornean orangutan, Pongo pygmaeus, was declared critically endangered in 2016; since the mid-20th century, its population has declined by more than 80 percent.
Populations of the Sumatran orangutan, Pongo abelii, and the Tapanuli orangutan, Pongo tapanuliensis, both of which are also critically endangered, have also experienced precipitous declines.
In response, a devoted group of caretakers is trying to unravel the complexities of conservation on Sumatra, fighting to protect the ecosystem and grasping for a solution that can mutually benefit both the wildlife and people who call the island their home.
Sumatra is a long way from my family’s ranch in Wyoming where I grew up on the outskirts of Grand Teton National Park. Conservation, however, is in my blood. Fifty-five years ago my great-grandparents recognized the importance of wild areas, and established our ranch as one of Jackson Hole’s first private conservation parcels.
It was growing up here that I fell in love with nature and learned firsthand the difficulties of protecting it as development encroached around us. As my careers as an environmental archaeologist and photojournalist matured, I grew interested in the relationship between wildlife conservation and traditional cultures. In 2017, I leapt at an opportunity to travel to Sumatra with Photographers Without Borders, a nonprofit that had been covering the island’s wildlife and Indigenous-rights issues.
Over the next several weeks, we traveled through North Sumatra under the guidance of the Orangutan Information Centre (O.I.C.), an organization that aims to rescue injured and trafficked orangutans, rehabilitate destroyed rain forests and help circumvent human-animal conflict through educational programming.
Panut Hadisiswoyo, who founded the O.I.C. in 2001, told me that his goal is to give orangutans on Sumatra a place to flourish. He also hopes that, through community development, he can instill pride and awareness about the animals in rural communities — to help create a group of grass-roots orangutan guardians.
The epicenter of the O.I.C.’s efforts are in the Leuser Ecosystem, whose rain forests provide livelihoods and drinking water for more than four million people — and whose boundaries are continually threatened by ever-expanding palm oil plantations.
With the assistance of Nayla Azmi, a 32-year-old Indigenous conservationist, we spent several days hiking through the mountainous rainforest to watch and photograph families of orangutans on the outskirts of Bukit Lawang, a small village whose eco-tourism-driven economy provides a case study on how sustainable jobs and forest preservation can coexist.
Following our time with the orangutans, Ms. Azmi led us to other corners of Sumatra to learn about less iconic but equally important conservation battles.
Near the remote village of Tangkahan, which sits on the edge of Gunung Leuser National Park, a riverside animal rescue center is home to a family of Sumatran elephants rescued from forced labor operations. While their new riverside home was bare-bones and relies on the controversial practice of offering elephant rides for income, the rescue center works to provide the animals with a better environment, in spite of mediocre resources. Visiting the center was a testament to the reality of conservation in Indonesia, where good intentions are often constrained by economic and infrastructural limitations.
The fate of Sumatran conservation will largely be determined by what happens in the next few years. While the rate of forest destruction continues to increase, the tireless work of activists like Mr. Hadisiswoyo and Ms. Azmi offers glimmers of hope.
“My dream is to see Indigenous people reclaim their pride and begin to lead conservation programs,” said Ms. Azmi, who recently founded the Nuraga Bhumi Institute to help preserve Batak culture, promote women’s rights and campaign for Indigenous-led conservation efforts.
“If we can give the trust to the people, if we can work together and take pride in our ancestral connection to the forest, I believe we will see a great change in conservation on Sumatra.”
Matt Stirn is an archaeologist and photojournalist based in Boston and Jackson Hole, Wyo. You can follow his work on Instagram.