Biologists at Durham University spent four months recording gibbon calls . The recordings revealed that the monkeys were able to distinguish between different types of sounds - from a single note to an entire song.
Biologists at Durham University spent four months recording gibbon calls . They recorded gibbons making 450 'hoo ' calls from 25 animals that were impossible to distinguish with the human ear and were often inaudible . Each call was found to relate to different contexts like foraging , meeting neighbours , singing to mates or warning others about a predator nearby . Hoos about birds of prey were the quietest so not to alert the predators .