All subspecies of gorilla are endangered. Western lowland gorillas are the most numerous, with an estimated population of about 175,000 individuals. The populations in Equatorial Guinea and Nigeria are critically endangered. The eastern lowland gorilla population is estimated at 5,000 to 10,000 individuals.
Population estimates for both western and eastern lowland gorillas are based on habitat availability and actual populations are probably lower. There are approximately 700 total mountain gorillas (both subspecies) based on population censuses, some groups of which are critically endangered.
The Cross River gorillas are found in five small pockets of habitat along the border of Nigeria and Cameroon and number approximately 150 animals. A reduction of 80 percent in the next ten years is estimated by some conservation organization estimates. This estimate is based on the decline in quality of habitat.
As of November 2009, there were 337 gorillas in North American facilities, and the world zoo population was about 750 gorillas. Almost all zoo gorillas are western lowland. The only eastern lowland gorillas in captivity live in Europe. There are no mountain gorillas in zoos.
Threats to gorillas come from humans. The political instability in central western Africa has led to a decline in the number of gorillas. Humans kill individuals in order to capture young, to get trophy body parts (less so now), and for bush meat. The greatest threat to gorillas, and all apes, is from habitat destruction caused by logging and agricultural expansion.
The bushmeat trade, facilitated by logging, has become an immediate threat to the western lowland gorilla population. In one year alone approximately 2,000 gorillas were killed for bushmeat. Another great pressure is being put on mountain and eastern lowland gorillas due to war and refugee movements.
There are international guidelines and laws to protect gorillas. Notably, the World Conservation Union has developed criteria to identify threatened species and drafted the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), under which trade in gorillas or gorilla parts is illegal. There are also national laws and programs to protect gorillas. See the Conservation section for more details. Unfortunately, compliance and enforcement remain problematic.
Gorillas at the National
The National Zoo exhibits six western lowland gorillas in the Great Ape House. They live in one family group.
Species Survival Plan
The gorillas at the National Zoo are managed under a Species Survival Plan. The Zoo has experienced successful breeding of gorillas.