The silverback—the dominant adult male of a mountain gorilla family group—is the structural centre of the social unit. He makes decisions about where the group moves, mediates conflicts between members, defends the group from predators and rival males, and fathers the majority of the group’s offspring. When a silverback dies, whether from disease, injury, old age, or inter-group conflict, the consequences for his family can be severe and sometimes catastrophic. Understanding silverback succession—the processes by which a gorilla family responds to the loss of its dominant male—reveals some of the most dramatic and tragic dynamics in gorilla social life.
The silverback’s role in group cohesion
Adult females in a gorilla family are not bonded to each other—they are bonded to the silverback. The social glue of the group is the females’ individual relationships with the dominant male rather than female-female affiliative bonds. This means that when a silverback dies, the group has lost its primary cohesion mechanism. Without his presence, females may disperse to other groups, juveniles may be at increased vulnerability, and the group as a social unit may dissolve entirely rather than continuing under new leadership.
This contrasts with chimpanzee and human social structures, where female bonds and coalitions among males create social networks that persist independently of any single individual. The gorilla’s more linear social structure—centred on the dominant male—creates this succession vulnerability that makes each silverback’s life critically important to the survival and reproductive success of his entire family.
Infanticide: the most severe succession outcome
When a lone silverback dies and has no successor within the group—either a maturing blackback son or a second silverback who has been part of the group—females with young infants become vulnerable to infanticide. Infanticide by incoming males is documented across multiple gorilla populations and represents one of the most disturbing aspects of gorilla social biology. A new male who takes over a group by killing nursing infants brings the females into estrus sooner than they would otherwise come (lactation suppresses ovulation), allowing him to father his own offspring faster. The evolutionary logic is stark: from the perpetrating male’s genetic perspective, the act is adaptive; from the perspective of the killed infant and its mother, it is catastrophic.
In Bwindi’s habituated groups, silverback succession events have been monitored closely, and veterinary intervention has occasionally been possible when infant vulnerability following a silverback death was identified. The ability to intervene—treating injuries, providing supplemental food during social disruption, or in extreme cases temporarily separating vulnerable individuals—is one of the concrete benefits of habituation and the monitoring it enables.
Successful succession: multi-male groups
The most stable succession scenario is a multi-male group in which a younger silverback—typically the eldest son of the dominant male—has been integrated into the family. When the dominant male dies or is incapacitated, this subordinate silverback is already known to the females, has social relationships within the group, and can assume leadership without the infanticide risk posed by a stranger male. Several long-studied Bwindi families have demonstrated this succession path successfully, with the dominant male’s son maintaining group cohesion and eventually taking over reproductive dominance.
For gorilla trekkers, encountering a group with multiple silverbacks—visible as two large, silver-backed males of different ages within the same family—provides a glimpse of this succession preparation. The interaction between the dominant and subordinate silverbacks, the way females position themselves relative to each, and the careful management of the subordinate’s role that the dominant male maintains are all visible in the dynamics of a multi-male family’s daily behaviour.
