What to know about endangered gorillas and tourist tours tracking them

Big Ben, 12 years old, an endangered high mountain gorilla from the Sabyinyo family, walks past a warden inside the forest within the Volcanoes National Park near Kinigi, northwestern Rwanda. The last global survey in the Democratic Republic of Congo, Uganda and Rwanda in 2010 found just 480 individuals of the critically endangered sub-species. REUTERS/Thomas Mukoya