Chimpanzees use high ground to scope out rival groups

Groups of chimpanzees patrol the edges of their territory and pause on hilltops to listen out for rivals, judging whether it is safe to venture further

​Groups of chimpanzees patrol the edges of their territory and pause on hilltops to listen out for rivals, judging whether it is safe to venture further Groups of chimpanzees patrol the edges of their territory and pause on hilltops to listen out for rivals, judging whether it is safe to venture further