Male gorillas develop a saddle-shaped area of silvery hair on their backs when they reach sexual maturity. Silverback gorillas’ silvery fur is for display, and communicates to other gorillas that they are adult males. Many other species have equivalent markers performing this function – for example, facial hair in male humans, or manes in male lions.
A typical gorilla family consists of a dominant silverback male, sometimes other silverbacks (which support the dominant male), younger blackback males, adult females, juveniles and infants. The dominant silverback plays an important role in keeping the group together, as well as protecting it.
Rebecca Machin, Curatorial assistant of Natural Sciences at The Manchester Museum