We are deeply saddened to report that 24-year-old dominant silverback Isabukuru was found dead on Sunday March 26, 2017. Isabukuru’s case is atypical and the cause of his death remains unknown. For the past two years he showed signs of illness from frequent episodes of diarrhea, but his body condition and behavior appeared to be normal. During the last three months, Fossey Fund staff reported that Isabukuru seemed to being losing muscle mass and strength, and continued to monitor him closely with stool analysis and regular veterinarians’ assessments from Gorilla Doctors. Fossey Fund staff also noted that Isabukuru’s resting times had increased and that various females were emigrating from the group, which can be an indication of the group leader’s weakness.
On March 24, 2017, an experienced team composed of veterinarians from Gorilla Doctors and the Rwandan Development Board (RDB) along with Fossey Fund trackers and researchers performed an intervention on silverback Isabukuru. This intervention served as a hopeful last effort to save his life from a condition which remains to be unknown.
Kubaha, the second silverback of the group, has taken over and is leading the group peacefully so far. Silverback Kubaha is also taking care of the three young gorillas who were “adopted” by Isabukuru, as their mothers transferred to other groups while they were still very young. The Fossey Fund trackers will continue to monitor Kubaha every day in the hopes that he will continue a peaceful takeover of the group.
Caring for young gorillas was just one special aspect of Isabukuru’s personality and history. He was a brother to silverback Cantsbee, who was the longest-reigning, most-successful of the silverbacks studied by the Fossey Fund over its 50-year history. Secondly, he was exceptionally large for his age and very popular among females, even as a younger blackback. He broke away from the group led by Cantsbee in 2007, and started his own group at the young age of 14, taking three females with him.
The Fossey Fund is awaiting further analysis from Gorilla Doctors as to the cause of death in the hopes of informing similar cases in the future.