The gorilla is the largest of all living primates and consists of two species, the Eastern gorilla or mountain gorilla (Gorilla beringei) and the Western lowland gorilla (Gorilla gorilla). The Western lowland gorilla is the smaller of the species. A male standing erect can be 5–6 feet.
The Western lowland gorilla is listed as endangered and is found in the tropical forests of western Africa, from southern Nigeria to the Congo River.
Gorillas are mainly active in the morning, and they are peaceful and very social and prefer to live together in family groups or troops with 2 to 20 individuals. The troops consist of one dominant male or silverback and several females and their offspring.
In the 1980s the gorilla population in equatorial Africa was thought to be 100,000. However, surveys conducted by the Wildlife Conservation Society in 2006/7 found about 125,000 previously unreported gorillas living in the swamp forests in the Republic of the Congo. But gorillas remain vulnerable to Ebola virus, deforestation, and poaching.
Worldwide zoo population is around 550 Western lowland gorillas and the Cincinnati Zoo has a successful breeding program.