As fires rage in Borneo, several of the world’s rarest primates are continually threatened

A nonprofit environmental group working with primates in Sebangau National Park says the dry peatlands can be a catalyst to more destruction.(CN) — Since early August, wildfires have devastated the fragile rainforests of Borneo and Sumatra, causing widespread toxic air across Indonesia. It’s affected most communities in all parts of the region of Kalimantan, a part of the world’s third largest island under Indonesia’s governance.The fires are fueled by shifting El Niño climate patterns, causing severe drought and extremely dry conditions in the island’s peatlands, among the planet’s most effective carbon-capturing ecosystems and vital habitat for wildlife found nowhere else in the world.Sebangau National Park in Central Kalimantan is home to an estimated 6,000 to 9,000 critically endangered Bornean orangutans, one of the island’s largest populations. The nonprofit Borneo Nature Foundation said a fire crossed the park boundary for the first time in early September.“Our teams pushed it back, and it was largely confined to sedge and open peat, but some reforestation sites are impacted,” Dr. Susan Cheyne, the Science Director for the Borneo Nature Foundation and the Vice Chair for the International Union for the Conservation of Nature special project group for small apes, said in an email to Courthouse News.A member of the Central Kalimantan local firefighting crew combats the flames. (Renhat Bonxy/Borneo Nature Foundation Indonesia.)“Our priority is to keep fire out of the forest, because that protects every orangutan in it at once,” she said. Cheyne and her colleagues monitor and document conditions in Borneo, while volunteer firefighting crews work to keep fires out of orangutan habitat and nearby villages. Capturing and removing the apes is “a last resort,” Cheyne said.Sebangau is also home to several of the world’s rarest primates, including the largest known population of Bornean white-bearded gibbons, an ape Cheyne has studied for over 20 years.Gibbons are known for their musical vocalizations, or “songs.” Males sing alone in the morning before females join them in duets later in the day.“During the 2006 fires I found that gibbons sang less often and sang shorter songs on smoky days. Their song is how they defend territory and keep pair bonds, so this matters,” said Cheyne. “A similar pattern has since been recorded in wild Bornean orangutans exposed to wildfire smoke.”A Bornean white-bearded gibbon sits in a tree. (Courtesy of Borneo Nature Foundation.)Gibbons rarely come to the ground, and fire survivors are often left in small, isolated forest patches with little food. Other primates, including red langurs and long-tailed and southern pig-tailed macaques, are found only in Southeast Asia, and each fire further reduces their numbers. Little is known about how fires affect nocturnal slow lorises and western tarsiers, Cheyne said.The national park includes vast peat swamps, made of partly decomposed plant material accumulated over thousands of years. In parts of Sebangau, the peat dome reaches 12 meters deep.Peatlands are naturally waterlogged, like giant sponges that do not burn. But in the 1990s and early 2000s, illegal loggers dug hundreds of canals to float timber out of the forest. Those canals continue draining the peat, causing it to dry out and become fuel.“In a long dry season like this one, a dried-out peat swamp is a tinderbox,” said Cheyne.“What makes peat fires so hard to fight is that they burn downwards and sideways, not just across the surface. Fire smolders underground through the dry peat, sometimes for weeks, long after the flames above have gone out. These are sometimes called zombie fires.”Peat fires are particularly dangerous because from the surface, a person may see nothing amiss, perhaps “just a thin wisp of smoke,” Cheyne said, while a meter below the peat burns and can set nearby tree roots aflame, easily toppling them. And peat fires also produce dense, toxic smoke.Members of a firefighting crew hose flames near Sebangau National Park in Borneo. (Renhat Bonxy/Borneo Nature Foundation Indonesia.)Cheyne said since 2015, the foundation and local crews have built over 1,000 dams to block drainage canals, planted almost a million trees, drilled hundreds of water boreholes, and increased support for up to eight fire teams.“That preparation is why we are holding,” she said. But it’s still a tenuous situation. For the short-term, Cheyne said, the goal is to keep the firefighting teams in the field fed, equipped and safe, which costs about $100 a day per team. It also means investing in equipment, such as thermal drones that can detect underground peat fires and rewetting the peat, so it doesn’t reignite. The foundation, she said, is actively seeking donations from international bodies, advocacy groups and concerned individuals.While hotspots in Kalimantan have declined since the beginning of the month, according to the foundation, rains are not expected until late October or November.“We are not out of this yet,” said Cheyne.Cheyne said Borneo Nature Foundation International’s cofounder Simon Husson recently passed a troop of monkeys on a river trip and they moved through trees beside mile after mile of burned riverbank.“That is the picture,” she said. “Life hanging on right at the edge.”Subscribe to our free newslettersOur weekly newsletter Closing Arguments offers the latest about ongoing trials, major litigation and rulings in courthouses around the U.S. and the world, while the monthly Under the Lights dishes the legal dirt from Hollywood, sports, Big Tech and the arts.Additional Reads