One fresh start had come late in 1972—the sixth year of my study—when a new "man" entered my life. He was a cantankerous, grizzle-haired silverback, a likable tramp who showed up in the range of Group 5, a gorilla family that lived close to camp.
A student helper rushed in to tell me about the interloper. "I think he's a lone silverback, an older one." (A male gorilla is called a silverback when, at about age 11 to 13, the hair turns gray to silver across his back.)
"Nonsense!" I replied. "Old silverbacks never travel alone. They always stick to their own groups."
I was certain that the animal we came to call Nunkie would turn out to be one of Group 5's younger, peripheral silverbacks, those destined to break away from their home groups to win outside females and start families of their own.
How wrong I was! Nunkie, whom we estimated to be in his mid-30s, was a complete stranger. He didn't match our nose-print sketches (of lined indentations above the nostrils) or photographs of known gorillas.
How Nunkie turned things around—for my research and for the groups I was studying! He opened our eyes to the way gorilla families form and grow. The studies shed new light on previously suspected gorilla behavior, from simple intergroup transfers to the deadly drama of infanticide.
For 13 years I lived with mountain gorillas on the misty slopes of the Virunga volcanoes, which form a section of the borders between Rwanda, Zaire, and Uganda . In a study area of 25 square kilometers around my forest camp 3,000 meters up on Mount Visoke, several groups of these largest of the great apes have become habituated to my presence.