Critically EndangeredGorilla gorilla gorillaUnknown4 to 5 1/2 feet, up to 440 poundsThe most widespread and numerous of all gorilla subspecies, the Western Lowland Gorilla can be found across Cameroon, the Central African Republic, the Democratic Republic of Congo and Equatorial Guinea and in large areas of Gabon and the Republic of Congo. Because they inhabit some of the densest parts of Africa's rainforests, their exact population numbers are unknown.Western Lowland Gorillas are slightly smaller in size than other gorilla subspecies and have brown-grey coats and auburn chests. Over the last 20 to 25 years, Western Lowland Gorillas have seen their populations decrease by 60 percent due to poaching and disease. According to the World Wildlife Fund , "even if all of the threats to western lowland gorillas were removed, scientists calculate that the population would require some 75 years to recover."