This is the fourth in a series of articles presented by the Fossey Fund’s Gorilla Program Senior Advisor Veronica Vecellio, focusing on the mountain gorilla groups that the Fossey Fund protects and studies every day in Rwanda. Veronica has worked with these gorilla families for nearly 20 years and we are excited to share her amazing knowledge and insights about their lives.
The group named after silverback Ntambara has a long history that goes all the way back to one of the groups that Dian Fossey started studying 55 years ago. It is related to her study Group 5 and formed as the result of a split and later evolutions of leadership. The many stages that bring us to the current group all share a common thread, however, which is the presence of multiple strong males keeping the groups safe and cohesive.
Group 5’s historic split
In 1993, Fossey’s Group 5 split into two groups after the death of its dominant silverback, Ziz. The new groups were called Pablo group and Shinda group, for their original dominant silverbacks. But even though they had a common origin, these two groups then followed very different paths. They even moved to different parts of the forest and never interacted again during the 30 years since, other than two short episodes in 2003.
The gorillas in Shinda’s group (which now includes the Ntambara gorillas) exhibit the dominant attitude of their original leader, silverback Shinda. He was a vigilant silverback with an aggressive leadership style. Those of us who knew him were always anxious and wary when in his presence.
On the contrary, the gorillas who joined the Pablo group reflect the influence of its main leader – historic silverback Cantsbee, who took over from Pablo. Cantsbee was known for his gentle leadership and for wielding power without aggression.
Ntambara group’s influences
So today, it’s the influence of Shinda that is seen in Ntambara’s group. Although Shinda was an aggressive leader, he was also very effective at keeping his group together and was quite attractive to females. He grew his group to 28 members and was tolerant of other males in the group, who did not challenge him for leadership.
However, when Shinda died in 2008, the challenge for dominance started. The males of the group started acting differently – they all seemed to feel they could be his successor – and the group gradually split into two.
One part was led by Ntambara, with nine members and one was led by Ugenda, with 19 members. There were then months of separations and reunions, during which some members went back and forth, before the permanent split was accomplished.
Silverback successions
At the time Ntambara’s group was established, the family also included his silverback brother Ugutsinda, and young blackback Twibuke, who was still too young to enter in the hierarchy. Unfortunately, after a few years of leadership, Ntambara died, leaving the leadership to Ugutsinda. When Ugutsinda also died, Twibuke was left to inherit the group, without having ever shown any willingness to be at the top of the hierarchy.
Twibuke was only 17 then, but he quickly grew into his role of dominant silverback. Although his earlier behavior was patterned after his father, Shinda, as soon as he gained dominant status he became calmer and focused on keeping the group safe. And under his leadership, the group has grown to its current 14 members, with four infants and four females. Two younger silverbacks are great helpers as well.
It is always wonderful to observe the dynamics of Ntambara’s group. They often interact with another group that lives nearby, called Umubano, and it’s usually peaceful and a time for all the infants to play together. This is unusual since we generally only see these types of interactions among families that had previously lived together, which these two have not. We also love seeing the strong bonds among the females.
We are extremely proud to have such a wealth of information about the history of this group – especially the silverbacks. We have learned so much from them and this knowledge has helped us better understand the conservation needs of this endangered species.
