The western lowland gorilla has a brownish-gray pelage color with reddish highlights. The eastern lowland gorilla has a black pelage color. The mountain gorilla is black like the eastern lowland gorilla, but the hair is longer. The adult male who controls the group develops silver airs on his back, thus the name silver-back. In the western lowland gorilla these silver hairs also go down to the rump and thighs. The male has a sagittal crest which is larger than that of the female. The teeth of the gorilla have high crests that are used to help break down the leaves that make up a large proportion of their diet (Fleagle, 1988). This species has relatively long forelimbs and short hindlimbs (Fleagle, 1988). The gorilla has a short trunk and a wide pelvis (Fleagle, 1988). Individual gorillas can be distinguished from the nose, each gorilla has a unique nose pattern, like the human fingerprint.