Some 63 Penan communities came together to create 23 maps of their territory in central Borneo over the past 15 years.For three days in late November 2017, the Penan of the region celebrated the completion of the maps.The Penan now believe they are armed with the information that will help them hold on to their land in the face of pressure from outside timber and industrial agriculture interests. LONG LAMAI, Malaysia — The tallest tajem trees have slash marks clear up to the canopy. Each diagonal cut released some of the tree’s heart-stopping sap to tip someone’s darts, making him a more lethal hunter in the forests of Sarawak. The people of the Penan village of Long Lamai talk about the tajem trees the way they might about an old friend or family member. These poison trees, 26 of them, dot the homesteads of Long Lamai, on the banks of the Ba Balong River. In all, their trunks’ notched exteriors are more than just evidence of a people’s intimate relationship with the forest. They’re a living testament to their presence in these forests, stretching back generations. Unfortunately for the Penan of Long Lamai and dozens of other villages, these poison-dart trees aren’t a solid basis for a longstanding legal claim to the land. The roughly 16,000 semi-nomadic Penan who live along the tributaries that carved the topography of central Borneo have struggled for decades to keep a hold on their land in the face of incursions by timber companies, and more recently by palm oil and rubber producers. So for the past 15 years, they have developed a tool they hope will be proof of their enduring presence in the region.