Eastern gorilla
There are two recognised subspecies of eastern gorilla: the mountain gorilla ("Gorilla beringei beringei") of the volcanic slopes of Rwanda, Uganda and eastern Democratic Republic of Congo; and Grauer's gorilla or eastern lowland gorilla ("Gorilla beringei graueri") in eastern Democratic Republic of Congo.
Deception in animals
Tactical deception has been used as a measure of advanced social cognition as it relates to brain function. Primates have larger brains, relative to body size, than in any other mammal except for dolphins, and this size difference is mainly due to an enlarged neocortex. Research has suggested that the evolution of the primate brain is selected-for in highly social species. One study used 18 species with varying brain volumes (three strepsirrhines, four New World monkeys, seven Old World monkeys, and four ape species). The study used the frequency of tactical deception as a measure of social cognition, and it found a strong correlation between the use of social deception and size of the neocortex.