What is a Silverback Gorilla?

A silverback mountain gorilla is an adult male identifiable by the swathe of silver hair on its back. As well as this impressive signifier of maturity, they are famed for displays of aggression and dominance including whooping, charging, chest beating, tree slapping, and less commonly, physical duels.

 

A typical silverback weighs 430 pounds (195 kg) and stands 5 feet (1.5m) tall. Silverbacks are incredibly strong and can lift over 1763 pounds (800kg) of dead weight. That’s roughly twice as much as a well trained weightlifter. In the wild, a silverback uses its immense strength to fell trees in order to reach their fruits. This makes mountain gorillas a keystone species in Virunga, since they significantly affect the ecology of their environment.

    01
    The Dominant Silverback

    A dominant silverback is responsible for directing troop activities such as nesting, feeding and migration between seasonal feeding areas. While vying to retain and recruit females during clashes with other troops, a dominant silverback will defend members of his troop to the death.

    Despite a dominant silverback retaining mating rights over all females within his troop, higher ranking silverbacks in multi-male groups are often able to mate with a small proportion of females.

  • 01
    The Dominant Silverback

    A male gorilla matures into a silverback at around twelve years old. Although there can be multiple silverbacks within a troop, there is always one male that dominates over all other gorillas (except in rare instances of matriarch-led troops). In Virunga National Park, habituated families are normally named after the silverback leading the troop at the beginning of the habituation process – a method of conservation by which gorilla families become accustomed to close contact with humans.

  • 02
    The Silverback - Female Relationship

    Nevertheless, a dominant silverback will rarely choose sides in an all female dispute, for his ultimate goal is to foster conditions favourable to reproductive success.

  • 02
    The Silverback - Female Relationship

    Mature females regularly migrate between families to improve reproductive chances and avoid inbreeding. No matter the family a female belongs to, she will strive to have close contact and a strong bond with the dominant silverback. This helps prevent harassment from other males and reduces the threat of hostility from non-related females encountered through migration.

  • 03
    Blackbacks and Subordinate Silverbacks

    Internal conflicts between silverbacks normally constitute displays of aggression rather than physical contact. However fights do occur, sometimes to the death.

    Coalitions may lead to subordinate males preventing females from migrating during clashes with rival troops.

    Although it may appear the subordinate silverback is defending the position of the dominant silverback, his true motivation is to retain access to females within the troop in the hope of one day deposing the dominant silverback. An alternative to coalition forming or challenging for dominance is for a silverback to become solitary.

     

  • 03
    Blackbacks and Subordinate Silverbacks

    The ultimate goal of all silverbacks is to maximize chances of reproductive success by becoming dominant. A blackback is mature sexually but not physically strong enough to challenge for dominance. Once a male develops into a silverback he may then form a coalition with the dominant silverback or challenge for control of the troop.

Solitary Silverback

There are several solitary silverbacks roaming the slopes of the Virunga mountains. Park Rangers do their utmost to monitor them and the dynamics of families they interact with.

The desire to reproduce is thought to be the most common driver behind solitary male emigrations. Occasionally a solitary male may stumble upon an all-female group, as was the case in February 1998, when a solitary male is known as Munyaga briefly took control of the Zunguruka family following the death of its leader. Often, solitary silverbacks remain alone for many years, challenging dominant silverbacks from other troops along the way in search of females to form a troop with. Karateka is one of Virunga’s longest-standing solitary silverbacks, remaining solitary since 2001.

  • 1994
    Mareru disappears into the wilderness
  • 1998
    Karateka becomes solitary
  • 2000
    Karateka temporarily rejoins the family
  • 2009
    Mukunda becomes solitary
  • 2017
    Gourba becomes solitary
  • 2017
    Sebagabo becomes solitary
  • 1994
    Mareru disappears into the wilderness
    Mareru's parents were slaughtered by poachers in 1994. He subsequently disappeared into the wilderness. He was spotted again in 2002 as a blackback and then in 2005 as a silverback. He remains solitary to this day
  • 1998
    Karateka becomes solitary
    Following a clash with his brother Buhanga, 3 members of Karateka's troupe emigrated; turning him solitary.
  • 2000
    Karateka temporarily rejoins the family
    Karateka peacefully joins the Munyaga family, an extremely rare occurrence
  • 2009
    Mukunda becomes solitary
    Following a clash with Bageni, Mukunda; son of Rugendo; becomes solitary. His brothers and sisters are members of 2 families, Humba and Nyakamwe. He remains solitary to this day and has a reputation for raiding farmers' gardens.
  • 2017
    Gourba becomes solitary
    Son of Mapuwa and Kidole, Gourba remained in his family until 2017; when he became solitary. His brother Baseka is part of the Rugendo family.
  • 2017
    Sebagabo becomes solitary
    Sebagabo was born in 2004 to Mapuwa and Kagofero. In 2017, he decided to leave his family to become solitary. He is the brother of Baraka, Wathaut and Mikundi

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