Wildfires are currently threatening a vital research site in Indonesia's Gunung Palung National Park, home to one of the world’s longest-running studies of wild Bornean orangutans. The fires, which have already come within 200 meters of the Rangkong research station—a satellite of the larger Cabang Panti station—are now spreading through the surrounding forest. These research stations are located in a region that is home to hundreds of Bornean orangutans (Pongo pygmaeus), one of three orangutan species, with over 2,500 thought to live in the park. All three species of orangutans are critically endangered, and the fires are forcing them to flee their habitat. “Orangutans are fleeing from these forests. It’s just horrible,” said Prof Cheryl Knott, a biological anthropologist at Boston University who has led research at Cabang Panti for 32 years. The fires are largely the result of land-clearing practices that are common in Indonesia, but this year’s conditions have made the situation far more severe. An extremely strong El Niño—a climate phenomenon that warms sea-surface temperatures in the Pacific and disrupts weather patterns—has led to record heat and drought. In parts of West Kalimantan province, some areas have gone months without significant rainfall. This has made the fires more intense and difficult to control. Scientists at Cabang Panti have spent decades collecting detailed data on wild orangutans, following some individuals from birth to old age. Their research has uncovered key insights, such as the fact that orangutans give birth only once every eight years, the longest reproductive cycle of any mammal. The research station itself is a critical site for understanding tropical ecosystems and how they are responding to climate change. Without the long-term data collected there, scientists say, it will be harder to track the impacts of global warming on biodiversity. “Cabang Panti protects what has been, until now, one of the only truly ecologically intact tracts of lowland tropical rainforest in Borneo,” said Prof Andrew Marshall, an anthropologist from the University of Michigan who previously led research at the site. In a bid to protect the research station, more than 40 people—mostly local staff, field assistants, and villagers—are working around the clock to fight the fires. They have created firebreaks and set up a makeshift sprinkler system to keep the surrounding peat wet. Peat, a type of organic soil, can smolder underground for months after surface fires are extinguished, making it a persistent threat. “The issue has surpassed any local organisation’s capacity,” said Caitlin O’Connell, deputy director of the Gunung Palung orangutan conservation program. “We need large-scale water bombing and skilled firefighters.” Even if the station is saved, the survival of the orangutans remains uncertain. “The orangutans need the forest,” Knott said. “If all we have left is the building, what are we studying if the orangutans are all gone, and the food they have is all gone?” Indonesian meteorologists predict that the fire season will continue through October, with El Niño conditions expected to persist. “The hotspots are everywhere,” O’Connell said. “I don’t think it’s hyperbolic to say that what we thought couldn’t burn could actually completely disappear if we’re looking at these dry conditions going on for months.” Scientists are racing against time to protect both the research and the fragile ecosystem that supports one of the world’s most endangered primates.