Chimpanzees, unlike Brooklynites, aren't typically active after sundown. But in response to increased pressure from humans in Uganda's Kibale National Park, some chimps have adopted the dark in order to find food.
By setting up infrared camera traps near a crop field at the edge of the tropical forest, French and Ugandan researchers could keep track of the chimps' night moves. Large groups of chimpanzees - parties of about eight, rather than the usual groups of three who eat together during the day - would venture into a maize field, swinging over a trench via a fallen tree.
A handful of chimpanzees cross over the trench leading into a maize field during the day. (YouTube/PLOS Media)