Keeping track of orangutan populations is vital for their conservation, and researchers have new tech to help them. Thermal-imaging drones are being used in the Borneo forests to count the orangutan population there. The tech has been used to measure the luminosity of stars in the past, but now the drones are used to detect the heat coming from the great apes as they rest in their nests. Land clearing and poaching has left tens of thousands of wild orangutans dead, leaving the species critically-endangered.