Ape Adaptations:A gorilla knuckle-walking

       Gorilla gorilla has evolved many traits to help it survive in the dense forests of Africa. Having long arms and short legs gives the species a natural quadrupedal posture, which helps reduce stress on their bones and joints due to their great mass. They normally "knuckle walk" on the knuckles of their hands and the palms of their feet, but are also capable of walking bipedally for limited periods. 3,4

An anatomical drawing of a human skeleton and a gorilla skeleton


        Western Gorillas' large size means that they have very few natural predators. To support their sturdy bodies, they have relatively thick bones. 4 This drawing provides a comparison of the skeleton of a gorilla relative to that of a human, if both were in an bipedal position.

A mother Western Lowland Gorilla holding her infant, in a tree
        The hands of the Western Gorilla have fully opposable thumbs, while the feet each have an opposable hallux (the "big toe); this allows them to dexterously handle small objects and securely hold their infants. These features, along with their large muscles, also make them fairly good at climbing, and they will often do so to reach fruit and to build their nightly nests. Large adults take care to stay near the trunk of trees when climbing. 3,4

        As in all primates, the Western Gorilla's skull is made up of many bones. Most of these become fused together as a fetus and form the cranium, which houses their relatively large brains. An adult Western Gorilla's brain weighs an average of 17.8 ounces. 15

        The skull also protects the special sense organs of gorillas. As diurnal animals, they rely heavily on their sense of vision. Large orbits in the skull enclose the eyeballs on every side except the front and provide protection for these important organs. Eyes that face forward and are fairly close together give the Western Gorilla excellent depth perception, which is important when climbing in trees. The anatomy of their eyeballs is very similar to that of humans, with a complex retina containing rods and three types of cone cells packed into the area of the fovea, which allows for keen vision in full color. Olfaction and audition are also important senses in searching for food and in communication.
4 Learn more about how the Western Gorilla behaves and reacts to its environment here.

Question or Comments? Feel free to contact me at wussow.arik@students.uwlax.edu.       

Site designed by Arika Wussow, Last updated April 2008.

MultipleOrganisms.net          University of Wisconsin-La Crosse