Scienceline
February 29, 2016
When biologists venture into the dense, humid Sumatran rainforest to study orangutans, they must fight their way through swamps and up mountains lugging heavy equipment, looking up to the canopy for any sign of the rare apes. Fewer than 7,000 orangutans live on the 180,000 square mile Indonesian island, so days can go by without a single ape sighting, making research expensive and inefficient.