Western gorillas snack on caffeine-laced nuts and throw sticks at intruders
Western gorillas eat kola fruits and seeds that offer little protein but plenty of caffeine, and in Gabon some chew a shrub containing a hallucinogen. They usually flee from people, yet researchers in 2007 reported some hurling sticks and clumps of grass. Both subspecies are critically endangered, one down to a few hundred animals.
Gorilla gorilla lives in west-central Africa, cut off from its eastern relative, and is the second largest living primate after that species. Its coat is lighter, black to brownish grey with a brown forehead. Wild males stand around 1.67 metres and weigh 145 to 191 kilograms, while females weigh 58 to 72. Thomas Savage described the species in 1847, taking its name from the word Hanno the Carthaginian navigator reportedly used for hairy wild people he met on the African coast.
Groups range from two to twenty animals, led by a dominant silverback with several females and their young. Young males leave on reaching maturity, and females switch groups before they start breeding at eight or nine. Mothers nurse infants for three to four years, so a female raises a surviving offspring only every six to eight years. Home ranges can cover 30 square kilometres but are not defended. Wild western gorillas use tools and may live 40 years.
Fruit dominates the diet when it is plentiful, and gorillas travel farther in fruiting seasons. In the dry months of January to March they fall back on fibrous leaves and bark. Different groups eat different mixes of plants and insects, mainly termites and ants, hinting at local food cultures. Besides kola, they eat seed pods of grains of paradise, which may benefit their hearts, and iboga, whose ibogaine acts on the nervous system.
Nearly all belong to the western lowland subspecies, estimated at about 276,000, boosted by Wildlife Conservation Society surveys in 2006 and 2007 that found around 125,000 unrecorded gorillas in Congo's swamp forests. The Cross River gorilla on the Cameroon–Nigeria border numbers only 250 to 300, scattered across about ten sites. Ebola cut numbers in protected areas by a third between 1992 and 2007, and poaching, logging and slow breeding compound the danger.
Source: Western gorilla
