The Western Lowland Gorilla:
A comparison with humans and a critique of methods of study.
For thousands of years, men and women have strived to explain the why of their existence. To discover the reasons for how we act the way we do and what this knowledge can do to impact the way we live our lives in this complex society that we have created. One of the ways that science has begun to shed light on the inner workings of the human condition is through Primatology. Built from the words Primate which refers to a group of animals closely related to humans and logos which is a Greek word meaning ‘the study of’ Primatology’s goals include more than simply to amass data on the primate species. Rather a Primatologist observes data about primates in an effort to understand the primate species under their study and to relate that data back to the human condition so that we can learn more about ourselves through our evolutionary cousins. In recent years, Primatologists have done much research on all aspects of the life of the western lowland Gorilla, known scientifically as: gorilla gorilla gorilla (Fay, 1989). In this paper I will compare these primates, more precisely classified as great apes, to humans in an attempt to illuminate both differences and similarities between the two species. More specifically, I will focus on the social structure of the western lowland Gorilla, describing how these predominantly gentle creatures live in a society similar to that of humans in many ways. Finally, in my conclusion I will explore the methods that Primatologists use to study primates such as the western lowland Gorilla and whether those methods are biased towards or against the Gorillas. However, I cannot draw indelible conclusions about these subjects as I have had no time studying these animals in the field and have only the observations and writings of others from which to draw my data and form opinions.
The most common of the Gorilla species, there are approximately ten thousand to thirty five thousand western lowland Gorillas in the wild and five hundred and fifty individuals in captivity worldwide. They are found in Nigeria, Cameroon, Gabon, Congo, Central African Republic and Zaire in increasingly shrinking habitats due to the incessant encroachment of human populations.
Western lowland gorillas are covered with black or brown-gray fur with black skin on chests, palms, and faces. Red heads are common in Camaroon gorillas especially. Males develop a silver back as they mature this is not unlike the tendency for many human males to develop gray hair as they mature as well. The main difference being that only Gorilla males develop silver backs whereas in humans both males and females alike tend to lose their hair coloring with age.
Unlike humans, which are bipedal, walking on two legs, Gorillas are quadrupedal, they walk on all fours with the soles of their feet flat on the ground with the knuckles of the hands curled and planted on the ground (Schaller, 1963). Although they are mainly quadrupedal, gorillas can travel bipedally but generally no farther than approximately six meters (Schaller, 1963). This upright stance is used most often used for chest beating, to observe something of interest, or to reach an object (Schaller, 1963).
Gorillas recognize each other by their faces and body shapes. Each gorilla has a unique nose print which researchers can use to identify animals in the field (Schaller, 1963). This is very much like humans who recognize each other almost exclusively by visual identification of the facial features.
Gorillas sleep about 13 hours each night and rest for several hours at midday. They build new sleeping nests every night by bending nearby plants into a springy platform, usually on the ground or in low trees. When not resting, they spend most of their time looking for food and eating it.
Despite their fearsome size (three hundred to five hundred pounds for males and one hundred fifty to two hundred fifty pounds for females) and large canine teeth the western lowland gorilla is an herbivore. They consume over two hundred types of leaves, tubers, flowers, and fruit, supplemented with fungus and some types of insects. Gorillas do not drink water. They obtain all the moisture they need from the vast amounts of foliage they consume. Males consume approximately fifty pounds of vegetation a day (Elizabeth, 1990). This is very different from the omnivorous diet of the human species, which has often been observed stalking and killing a Big Mac. All joking aside though, a human’s daily diet contains considerably more protein than a Gorilla might consume in a week or more (Elizabeth, 1990).
A Gorilla has an enormous head, with a bulging forehead overhanging the eyes and a bony crest on top. The sagittal crest, which is especially noticeable in adult males, supports large muscles used to process the large amounts of vegetative matter in their diet. The Human skull sports no such sagittal crest and the jaw muscles are greatly smaller than those found in the Gorilla no doubt illustrating Human adaptation away from a diet consisting largely of coarse vegetable matter. This is also evident in the differences between Human and Gorilla dentition (teeth). Human teeth are very slight when compared to the massive molars that can be found in the jaws of the Gorillas, another important adaptation for processing plant material.
Having outlined several of the major differences and similarities between humans and the western lowland Gorilla, I would like to turn to examining the complex social structure of these creatures.
A typical group of Gorillas is made up of six or seven animals, usually one dominant male known as the ‘silverback’, several adult females, and offspring of various ages, from infants to maturing black backs (young males). The silverback offers protection to the females and offspring from predators and other strange male gorillas (Tutin and Fernandez, 1991). This is somewhat analogous to the role of the Human male in many family and extended family units across many Human cultures, which is largely a role of protection from enemies of the group. Although in many instances, the role of the Human male is extended to that of providing for the group as well as protecting it.
Sexually mature female Gorillas leave their family group to join lone males or other small mixed groups. This leads to the females in a band being unrelated and serves to encourage genetic dispersal among the groups avoiding excessive inbreeding. A maturing male leaves his family group (sometimes driven off by the dominant silverback) to establish his own group, to roam alone, or to join a bachelor group. These wandering males follow other bands in order to entice females to join them in the hope of founding a successful group and spreading their genes through many offspring. The last two sentences might well refer to Human males and with little alteration. Human males practice exactly the same kind of migrations in many human cultures where they eventually leave the group in which they grew up to seek their fortune and often a mate as well. Although it is possible the need to secure one’s fortune is driven by the need to be successful to woo a mate but that is of course a bit of speculation on my part.
When Primatologists study their subjects in the field and in zoos and parks, are they being unbiased in their appraisal of the animals they have taken upon themselves to study? I believe that as a human being it is impossible to separate oneself completely from the unique Human point of view. This leads to the interpretation that yes in fact Primatologists do make biased observations of the behaviors of these creatures. That they are appraising the Gorillas as Humans must, with human terms and human values on certain things that allow a species to have ‘language’ or ‘think’ or have a ‘culture.’ I do not believe that this is entirely a bad thing as it is important and natural for us to relate to objects, ideas, and indeed other species in terms that make sense to us. However the question remains, does the western lowland Gorilla have culture? The science of Anthropology defines culture as every thing we say, think, and do in our daily lives. The true limits on the use of the term culture then become how we define thinking, speaking, and doing things. If we must imagine beings in our own image then we are doomed to have no companions on this Earth and certainly none beyond it. However, if we broaden our minds and allow for the possibility of thinking, speaking, and doing things in a manner that is unlike our own, we may find there are more creatures with more rich and diverse cultures than we had ever imagined.
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Fay, Michael, et al. "Gorillas (Gorilla gorilla gorilla) in the Likoula Swamp Forests of North Central Congo: Preliminary Data on Populations and Ecology." Journal of Primatology, Vol 10, No. 5, 1989, pp. 477-486.
Fossey, Dian. Gorillas in the Mist. Boston: Houghton Mifflin Co., 1983.
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Rogers, M. Elizabeth, et al. "Gorilla diet in the Lope Reserve, Gabon: a nutritional analysis." Oecologia, 1990, pp. 326-339.
Schaller, George. The Mountain Gorilla. Chicago: University of Chicago Press, 1963.
Williamson, Elizabeth A. et al. "Composition of the Diet of Lowland Gorillas at Lope in Gabon." American Journal of Primatology, 21. 1990, pp. 265-277.
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