Gorillas - Population & Distribution

What's the outlook for the two gorilla species?

Current Population and Distribution - western gorillas
The western lowland subspecies of western gorilla is the most widespread and numerous gorilla, possibly numbering 100,000 individuals; however there are no accurate estimates of numbers as these elusive apes inhabit some of Africa’s densest and most remote rainforests. In some areas, it occurs in surprisingly high densities - e.g. almost three individuals per square kilometre in Cameroon's Lobeke National Park. However, the subspecies has disappeared from its former range in western Democratic Republic of Congo (DRC).

The Cross River gorilla subspecies is restricted to a small area of highland forest on the border of Cameroon and Nigeria. With a population of only around 300 divided into several subpopulations, some of which number no more than 20 individuals, it is probably the world’s rarest great ape.

Current Population and Distribution - eastern gorillas
Separated from western gorillas by about 900km of Congo Basin forest, eastern gorillas inhabit the upland and mountain forests of eastern Central Africa.

The eastern lowland gorilla subspecies (or Grauer's gorilla) occurs only in the DRC. There are no reliable estimates of their numbers due to lack of census data in remote regions, as well as the unknown impact of decades of civil conflict in eastern DRC. At one time the population could have reached 17,000; however the subspecies now occupies only about 13% of its original range. The largest protected population, in Kahuzi Biega National Park, has declined markedly in the past ten years due to war-related habitat destruction and hunting.

The total population of the mountain gorilla subspecies is about 700 individuals, split almost evenly into two groups: one in the Virunga range of volcanoes on the Uganda-Rwanda-DRC border, and the other in Bwindi Impenetrable National Park, Uganda. Thanks to conservation efforts, the Virunga population has increased by 14% in the last 12 years, while the Bwindi population has increased by 12% over the past decade. Despite this success, the subspecies remains threatened by hunting for meat, trophies, and live infants, as well as by habitat destruction and increased disease risks due to proximity to local populations and tourists. Some primatologists believe the Bwindi gorillas may be a separate subspecies.