A male orangutan, clinging precariously to overhanging branches, flails the water with a pole, trying desperately to spear a passing fish.
It is the first time one has been seen using a tool to hunt.
The extraordinary image, a world exclusive, was taken in Borneo on the island of Kaja, where apes are rehabilitated into the wild after being rescued from zoos, private homes or even butchers' shops.
"Orang hutan" means "forest man" in one of Indonesia's many languages and our long-armed cousins do indeed show a remarkable ability to mimic our behaviour.
This individual had seen locals fishing with spears on the Gohong River.
Although the method required too much skill for him to master, he was later able to improvise by using the pole to catch fish already trapped in the locals' fishing lines.
The image is part of a series taken for a new book, The Thinkers Of The Jungle, which also includes the first photograph of an orangutan swimming.