One Does Not Simply…Write About Anthropology

My Time as a Graduate Student

Final Primatology Presentation

on April 26, 2013

As the semester winds down, this is the time for presentations, last minute panic to write papers that you were aware of since the beginning of the semester, and exams. Yesterday I did my presentation on my Primate Zoo Project, I figured I would share the Prezi and and presentation notes. Remember Primatology is just one field of study for anthropologists, specifically biological anthropologist. Why? Primatologist study our closest relatives, apes and monkeys, to get an idea of how our behavior in the past, before the apes/human split and before human evolved into the anatomically modern human – what we are today. Although we may never truly know how early humans may have acted, we can only speculate based upon the behaviors of apes and monkeys.

So I give you, gorillas.


Introduction/Why Study Gorillas:

Hollywood has portrayed the image of the gorilla in various ways ranging from being meat-eating, ferocious beasts to caring, shy majestic creatures. Like most information in society, knowledge of gorillas comes from two places, movies and the internet. As it is known, movies are for the entertainment factor and have badly portrayed the image of gorillas in vehicles such as King Kong or Planet of the Apes, where the interpretation that has been implanted into viewers’ minds is that they are monsters.

I have always been fascinated with gorillas because of how largely misunderstood they were by a large number of people through the images of movies and how these images clash with the reality of the nature of gorillas. I chose to do my research paper and zoo observation of gorillas due to my fascination as well as my hope to spread the knowledge of these animals to help save them due to their pending extinction due to poaching, hunting, and habitat loss.

Previous Research

            George Schaller and Dian Fossey were two of the most influential individuals who, through their ground-breaking research, dismissed the public perception of gorillas as violent beasts. Little was known about gorillas in the wild before the 1960s. In 1959 George Schaller conducted the first long-term study of wild mountain gorillas (Gorilla beringei beringei) in the Virunga Volcano region of Central Africa for a year (Schaller 1963, Lang 2005). Schaller lived with his wife among the mountain gorillas studying their ecology, behavior, and life. Schaller published The Mountain Gorilla: Ecology and Behavior in 1963 that portrayed the intelligence, nature, and life of the mountains gorillas that was contrary to the popular belief of the time (Schaller 1963).

Six years later, the American zoologist, Dian Fossey, followed Schaller’s research of the mountain gorillas in the forests of Rwanda for over thirteen years (Fossey 1983). Fossey conducted one of the longest naturalistic studies of primates in the world and established the Karisoke Research Center to save the mountain gorillas from poaching, hunting, and extinction (Harcourt and Stewart 2007, Dian Fossey Gorilla Fund International 2013). Tradically, in 1985 Fossey was murdered in her cabin located in Rwanda.

Since Schaller and Fossey, there have been several studies of gorillas in the wild. But due to war and other violence in the region of Central Africa, it has been difficult to get consistent data on various groups of gorillas and many of the groups have fallen victim as casualties getting caught in the line of fire (Harcourt and Stewart 2007).


Like most primate taxonomy, gorilla taxonomy is controversial. Traditional classification that has been in place for over 30 years had gorillas in the subfamily hominoidea lumped together with orangutans, chimpanzees, and bonobos in the family Pongidae. Within this taxonomy there is only one gorilla species that is divided into three subspecies: western lowland gorilla (Gorilla gorilla gorilla), eastern lowland gorilla (Gorilla gorilla graueri), and mountain gorilla (Gorilla gorilla beringei) (Fossey 1983; Lang 2005; Schaller 1963; Harcourt and Stewart 2007). Knowledge of wild gorillas comes from twelve study sites in Africa: eight in west-central Africa and four in eastern Africa (Harcourt and Stewart 2007, Falk 2000).

An alternative taxonomy begins the genus in the family Hominidae with humans, chimpanzees, and bonobos. A new subfamily Paninae was created to distinguish gorillas from humans. This taxonomy then splits the genus into western and eastern gorillas. Western gorillas include two subspecies: western lowland gorillas (Gorilla gorilla gorilla) and Cross River gorillas (Gorilla gorilla diehli) (Dian Fossey Gorilla Fund International 2013, Harcourt and Stewart 2007). Eastern gorillas include two subspecies as well: mountain gorillas (Gorilla beringei beringei) and eastern lowland or Grauer’s gorillas (Gorilla. beringei graueri). There is not enough evidence to support this claim that the gorilla be split into two species with the controversies over mtDNA and interpreting the results of the molecular data (Harcourt and Stewart 2007). For consistency throughout this report, the traditional taxonomy will be followed.


            Geographically, gorillas are distributed throughout the countries of Central Africa. Populations are estimated upon night nest counts in known areas of habitats (Lang 2005).

The eastern lowland or Grauer’s gorillas are located in between the mountains and lowlands of the eastern Democratic Republic of the Congo. These gorillas are named after the scientist, Rudolf Grauer who first discovered the species, but little is known about them (Dian Fossey Gorilla Fund International 2013). It has been estimated that there are fewer than 5,000 eastern lowland gorillas due to habitat loss and poaching in the recent years (Lang 2005, Dian Fossey Gorilla Fund International 2013).

There are about 700-880 mountain gorillas in the wild and they are separated in two populations (Dian Fossey Gorilla Fund International 2013). The first population of mountain gorillas is located in the forests of the Virunga Volcanoes that are shared by the countries of Rwanda, Uganda, and the Democratic Republic of the Congo. The second population lives in the forests of Uganda (Schaller 1963, Fossey 1983, Dian Fossey Gorilla Fund International 2013). Fossey established the Karisoke Research Center in Rwanda’s Volcanoes National Park, which is still in operation today with ongoing studies of the mountain gorillas as well as the other subspecies (Fossey 1983, Dian Fossey Gorilla Fund International 2013).

The most common gorillas found in zoos are the western lowland gorillas. In the wild, these gorillas are located in the Central African Republic, Republic of Congo, Cameroon, Gabon, and Equatorial Guinea. The population is estimated to be about 150,000-200,000 gorillas left in the wild (Dian Fossey Gorilla Fund International 2013).

The addition to the alternative taxonomy, the Cross River gorillas are located in an isolated forest area of Cameroon and Nigeria.  The estimated population of the cross river gorillas is fewer than 300 in the wild

General Information

 Average lifespan of gorillas in the wild is 30-40 years and in captivity, 50 years. Infancy is the most dangerous time in a gorilla’s life, only about 60% of mountain gorillas will make it into adulthood.

Gestations is about 8.5 months with usually interbirth intervals of about 4 years. But it may change if infant dies, female will return her sexual cycle.

Weight – Males and females are sexually dimorphic in body size. Average weight for males is about 400 lbs and females are from 160-215lbs.

Social Organizations – Polygymous usually with 1 male with multiple females and offspring.

Diet – folivorous of bamboo shoots, stems, leaves, roots, with termites and ants.

Personal Research

The North Carolina State Zoo in Ashboro, North Carolina is the home to a six member western lowland gorilla (Gorilla gorilla gorilla) troop. This group includes: Nkoski, the alpha male silverback; the pregnant adult female, Acacia; the adult female, Olympia and her seven-month-old infant son, Apollo; and the adult female, Jamani and her seven-month-old infant son, Bomassa. Nkoski is the father of both male infants as well as the father of Acacia’s future offspring.

The day that I had chosen to go to the NC Zoo, it was approximately 60 degrees and without any clouds or wind. Upon entering the zoo, the entire facility had experienced a power outage and resulted in some of the animals, including the gorillas, to be released into their enclosure later than usually scheduled. The gorillas were released and present in their enclosure at about 10:45 in the morning.

Each individual was given an identifying number: Individual 1-Nkoski the male silverback, Individual 2-Acacia the pregnant adult female, Individual 3 Olympia the female adult mother, Individual 4-Apollo the infant of Individual 4, Individual 5-Jamani the female adult mother, and Individual 6-Bomassa the infant of Individual 5. For consistency throughout this report, the individual’s numbers will be used instead of their name.

The observational technique that was used was instantaneous scan sampling at one minute intervals for two, thirty-minute periods. With this technique, notes of behaviors are quickly recorded onto the data sheets. This technique was appropriate for this observation to make comparisons of the behavioral patterns of the group as a whole and of each individual.

Data sheets include each individual’s location, posture, locomotion, and activity/behavior at each one minute interval for a thirty minute period. Each data sheet also includes space at the bottom of each sheet for notes and ad libitum sampling, the random and interesting behaviors that do not happen to occur during the one minute time frames. All observed behaviors were recorded onto the data sheets that were created specifically for this group of gorillas. The data sheets are divided into five categories: Individual, Location, Posture, Locomotion, and Activity/Behavior. Each individual is indicated by their corresponding number (1-6) and there are 30 intervals that indicated each instantaneous scan sample. There are two data sheet sessions, one for each 30 minute session.

From the enclosure diagram, one can see that this enclosure is spacious for the primates with three high grass areas, two play features, and a concrete play area that also holds water and food sources. The enclosure diagram is divided into 20 portions: columns A-E and rows 1-4. Using this diagram and the data sheets, one can determine where each individual spends most of his or her time and which areas are rarely used. The areas that were most frequently used were: B2, B1,C2, and C4. The areas that were never used include: A4, D1, D4, E1, and E4. All other areas had very little usage by the gorillas.


The main postures were stand, sit, and lying down. The male silverback spent about 80% of his time in C4 either sitting or lying down.

Locomotion: walk, ride, or no movement.


main activities included, eat, sleep, cling, explore, looking, groom, and play. Infants were the most active individuals. Both spend a majority of their time exploring – exploring with the mother would allow her infant to check out its surrounding area and start wandering on its own, but the mother would only allow the infant to go a few feet before retrieving them or when the infant would vocalize a distress call that sounded liked a whimpering puppy. They often explored the high grass areas. Mother was usually squatting and watching the infants. But what was interesting, the mothers would never interact with one another and at times it seemed as if they were trying to avoid one another by staying on opposite sides of the enclosure during both my observational sessions.


The idea of captivity in zoos may be appalling to many, but captivity is allowing these animals to survive that would otherwise be facing the dangers of poaching or habitat loss. From my observations at the NC Zoo, the enclosure the gorillas were in was very spacious and the animals were able to go about their daily activities. The gorillas were breeding within the troop and the infants were not faced with the danger of infanticide that they could have been the victims of in the wild. In contrast, the opposing side to captivity is that these animals would not be performing natural activities that they would in the wild and thus could never be released into the wild. But the survival of these primates, in my mind, outweighs the cons. I also see zoos as a way of teaching the public. I am sure that no one would like to be watched and be stared at through the glass as one goes about their daily lives, but this opportunity can be a teaching tool. At the NC Zoo, there are signs explaining the subspecies of the gorilla, the members of the group, and the dangers that the wild gorillas face. The caretakers of the gorillas are also present in the observational viewing areas to explain daily activities and answer any questions the public may have about these majestic primates. Zoos are a conservational tool that is employed to maintain the survival of these apes.

There are many conservation projects that exist to try and save the gorillas in the wild that include the Fossey Fund and the International Gorilla Conservation Program (Lang 2005, Dian Fossey Gorilla Fund International 2013). Between the years of 1989 and 2003, the mountain gorilla population increased by 17 percent and this increase occurred with an area that is protected by the Fossey Fund (Dian Fossey Gorilla Fund International 2013). By 2010, the mountain gorilla population increased again by about 26 percent in the same area (Dian Fossey Gorilla Fund International 2013).

Prezi Presentation:


Dian Fossey Gorilla Fund International, Inc.

2013  Learning About Gorillas. (accessed Feb 18, 2013).

Doran-Sheehy, D. M., Greer, D., Mongo, P. and Schwindt, D.

2004  Impact of ecological and social factors on ranging in western gorillas. Am. J. Primatol., 64: 207–222. doi: 10.1002/ajp.20075

Falk, Dean.

2000  “Gorillas: The Largest Primates of All.” Chap. 12 in Primate Diversity, by Dean Falk, 298-317. New York: W.W. Norton & Company.

Fossey, Dian.

1983  Gorillas in the Mist. New York: Mariner Books.

Harcourt, Alexander H., and Kelly J. Stewart.

2007  Gorilla Society: Conflict, Compromise, and Cooperation Between the Sexes. Chicago: The University of Chicago Press.

Lang, Kristina Cawthon.

2005  Primate Factsheets: Gorilla (Gorilla) Taxonomy, Morphology, & Ecology . October 5, 2005. (accessed February 17, 2013).

Maple, Terry L., and Michael P. Hoff.

1982  Gorilla Behavior. New York: Van Nostrand Reinhold Company.

Rothman, Jessica M., Ellen S. Dierenfeld, Harold F. Hintz, and Alice N. Pell.

2008  “Nutritional Quality of Gorilla Diets: Consequences of Age, Sex, and Season.” Oecologia ( Springer in cooperation with    International Association for Ecology) 155: 111-122.

Schaller, George B.

            1963  The Mountain Gorilla: Ecology and Behavior. Chicago: The University of Chicago.

The Gorilla Organization .

2013  n.d. (accessed February 17, 2013).

Weber, Bill, and Amy Vedder.

2001  In the Kingdom of Gorillas: Fragile Species in a Dangerous Land. New York: Simon & Schuster.






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