The habits of one of the world's least-studied monkeys have been revealed by a BBC film crew.

Led by primatologist Dr Julie Anderson, the crew caught up with a troop of elusive red-capped mangabeys living in the forests of Gabon.

Despite being a large, vocal monkey, this species has rarely been filmed in the wild, and has never been properly studied by scientists.

Living with Monkeys is broadcast on BBC One each Tuesday at 2100.