Eastern gorilla
Grauer's gorillas and mountain gorillas were previously thought to be two of the three subspecies of one single species, the gorilla ("Gorilla gorilla"). However, genetic research has shown that the two eastern subspecies are far more closely related than the western subspecies: the western lowland gorilla ("G. gorilla gorilla"), which justified the separate classification. The two eastern subspecies are now classified as "G. beringei".
Greater bamboo lemur
Greater bamboo lemurs live in groups of up to 28. Individuals are extremely gregarious. The species may be the only lemur in which the male is dominant, although this is not certain. Because of their social nature, greater bamboo lemurs have at least seven different calls. Males have been observed taking bamboo pith away from females that had put significant effort into opening the bamboo stems. In captivity, greater bamboo lemurs have lived over the age of 17.
The greater bamboo lemur ("Prolemur simus"), is one of the world's most critically endangered primates, according to the IUCN Red List. Scientists believed that it was extinct, but a remnant population was discovered in 1986. Since then, surveys of south- and central eastern Madagascar have found about 500 individuals in 11 subpopulations. The home range of the species is likewise drastically reduced. The current range is less than 4 percent of its historic distribution. Most of the former range is no longer suitable habitat due to this species' dietary specialization on bamboo and its microhabitat preferences. The outlook is dire since areas with critically low population numbers have no official protection, and comprise severely degraded habitat. The species is endangered by the following: slash and burn farming, mining, bamboo and other logging, and slingshot hunting.