In pictures: Gorilla guardians

“Kabirizi” is the silverback of a 34-strong family, one of four groups Mr Kambale spends time with.

The rangers, who work for the Congolese wildlife authority (ICCN), risk their lives to protect the gorillas, despite small and irregular wages.

Since the start of the war in 1996 an estimated 120 rangers have been killed by rebels while on duty.

“Our job can be very dangerous, but if we were not here we are afraid no one would protect these rare animals,” says Mr Kambale.