Week 16: Tamarin Exhibit

ImageIn the Zoo Atlanta exhibit, the golden lion tamarins seem to have some space to play around in. The exhibit has plenty of branches for the tamarins to jump around on and climb. The walls on the zoo are painted to look like the tops of trees, but I feel like that is more for the enjoyment of the people visiting the zoos than it is for the tamarins since the tamarins do not gain any benefit from the paintings. Though the golden lion tamarins are small, I feel like Zoo Atlanta could enlarge the space more and give the tamarins more foliage and leaves to play on. It is very hard to get a good perspective on the size of the exhibit due to the paintings on the wall and the angle of the camera. I think it is important to note that Zoo Atlanta has been working with conservation groups to reintroduce golden lion tamarins into the wild. They have also helped fund a forest pathway to connect fragmented habitat. Golden lion tamarins typically live in groups of 2 to 8 individuals, usually made of one breeding pair and their offspring. From what I could tell of the Zoo Atlanta exhibit, the groups seems to be made up of 7 or 8 individuals, which fits the usually group size.

            From the angle of the camera, the only form of enrichment I am able to see are the branches the tamarins play on and a few swings for entertainment. The territory of a tamarin family is usually around 100 acres, far larger than the habitat they are currently living in. The tamarins maintain their territory through scent marking, vocalizations, and patrols. Observing the tamarins from the camera, the tamarins can be heard screeching to one another, but I doubt the purpose behind the screeching is to maintain their limited territory. During midday, tamarins can usually be seen resting, something that I have not observed in my time watching them. Instead, the tamarins seem to be bundles of energy, climbing everywhere and entertaining themselves. At one point, it almost seemed as if the tamarins were playing hide and seek; one tamarin could be seen on a branch with its head down, and as soon as it popped up, all the tamarins went running. I have also observed a few of the tamarins grooming one another, which is typical behavior of tamarins. I have also observed several of the tamarins scratching themselves vigorously, a behavior I did not expect. They also jump over one another, effortlessly overcoming any obstacle in their way.

            Reading on the food offered to tamarins in zoos, it was stated the foundation of their food was commercially canned marmoset food, which provides the minimum nutritional requirements for a tamarin. Zoo Atlanta also provides their tamarins with fruits, vegetables, and several types of worms to meet their protein requirement. I think that this exhibit does a good job promoting conservation for tamarin habitats. They donate money to help restore destroyed habitats and offers internships for helping this conservation. The Zoo Atlanta works with several institutions, such as the Smithsonian and the Brazilian government to help improve conservation efforts and work on reintroducing golden lion tamarins into the wild. While there is still much work to be done concerning conservation efforts, it is clear that Zoo Atlanta is willing to help work towards reaching that goal.

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Week 15: Fossey Archives

ImageLooking at the Fossey archives, I have decided to write about two letters Fossey wrote, one written on May 2nd, 1970 and the other was written on May 9th, 1970. In the first letter, Fossey was writing to a man named Louis, having just learned of the deaths of both Coco and Pucker, two gorillas she had saved and then was forced to give to a Kraut farm. In this letter, she is both extremely angry and sad. As Fossey describes it, she says, “it was bad enough that I had to release them to that god-damn Kraut farm a year ago today, but the fact that they couldn’t even take care of them for one year is indicative and further confirms my own belief that they had no right asking for them in the first place” (Fossey, May 2nd 1970). She proceeds to describe them as “martyrs” for the cause of conservation and how she is going to use their death as a means to push the government and others to work harder on conservation. She discusses how she wished she would have been able to keep them until they were ready to be released into the wild and then let them grow up in their natural habitat. Fossey was a big believer in allowing gorillas to stay in the wild, and actively sought to keep gorillas from being taken from the wild and brought into zoos for peoples’ entertainment. She was especially against this as the collectors would often have to kill all the members of a gorilla group in their attempt to collect a baby gorilla to bring to a zoo. Fossey proceeds to warn Louis about the actions she is about to undertake, saying that she has no control over herself when it comes to these matters. While Fossey’s enthusiasm and passion for the gorillas were what motivated her to do what she did, her actions often alienated those in positions to help her achieve her goals, which might have limited her success in her efforts to preserve conservation.

        Image    In the second letter written to Bob, Fossey discusses the case of a buffalo she was forced to kill after someone cut off its hind legs and left it trapped, but alive. She compliments to courage a strength the buffalo had and discusses her anguish in being forced to kill it. In response to this, Fossey tracked the people she thought were responsible for this deed and came across a child, whom she kidnaps in the effort to exchange him for the hunters’ spears. She is very aggressive and rude when describing these circumstances, shooting at the Tutsis and calling the child she kidnapped a “brat”. When making the exchange for the child, the hunter claimed that Fossey had already taken his spear, indicating that these actions made by Fossey were not uncommon. She then proceeds to discuss a different set of hunters, one whose brother Bob had shot. These extreme actions indicate the relationship Fossey had with the locals, further alienating people who were in positions to help her accomplish her goals.

            Today, I believe that we handle these instances better than Fossey did. Today, we do not kidnap children to accomplish our goals, instead we work with the government and the locals to achieve our goals. If researchers come across poachers today, they arrest them, not kidnap their children. Fossey’s actions, while for a noble cause, are not something that should be looked to as an example. Instead, we should search for peaceful solutions that would help both the local people and to enhance the efforts towards conservation.

Information from Fossey archives

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Week 14: Polyspecific Associations

ImageThe polyspecific association group I am focusing on for this e-portfolio is the group formed by red colobus monkeys and Diana monkeys, specifically in the Tai National Park, Ivory Coast. Here, the two monkeys spend the majority of their time together, roughly 62 percent. With this association, both monkeys alter their behavior. Diana monkeys alter their dietary habits, including more insects into their diet. The red colobus monkeys alter their grouping patterns by dispersing more, mirroring the grouping patterns of the Diana monkeys. By slightly altering their behavior, each monkey proves that he is willing to put effort into this association.

ImageRed colobus monkeys are arboreal, diurnal monkeys. Their diet largely depends on leaves, though they also eat certain flowers and fruits. Red colobus monkeys spend around 10 hours each day awake. These monkeys live in large group sizes, maxing out at around 100 individuals and breaking off into groups for feeding. Diana monkeys travel in much smaller groups, averaging around 14 individuals with the largest being around 50. They typical diet for Diana monkeys are fruits and insects, but also include flowers, leaves, and invertebrates. Diana monkeys also live in the trees, rarely coming to the ground. An interesting aspect of the red colobus monkey’s biology is their stomach, which contains 4 compartments. The red colobus monkey uses these compartments to break down their food. Both the Diana monkeys and the red colobus monkeys have specialized calls for warning individuals of danger, which can be advantageous if each monkey knows the calls of the other. 

Both the Diana monkeys and red colobus monkeys are prey for chimpanzees and large eagles. Diana monkeys travel lower in the canopy and it is believed that the red colobus monkeys protect the Diana monkeys from their aerial predators. In return for this protection, Diana monkeys spend more time on the edge of branches and serve as guards for terrestrials and arboreal predators. Due to threats from chimpanzees, Diana monkeys and red colobus monkeys most commonly form polyspecific associations during the rainy season, where hunting by chimpanzees is at its greatest. Tape recordings of chimpanzee vocalizations have shown the red colobus and Diana monkeys running distances to seek protection with one another upon hearing the sounds. The monkeys are also more likely to spend longer periods of time together if they hear or see a predator. The protection offered by each species makes it beneficial for both monkeys to remain in each other’s company for longer periods of time. Each monkey provides protection not just in looking out for predators, but also in combining their efforts in fighting off possible predators.

Competition for food and resources is minimal between Diana monkeys and red colobus monkeys. This could be due to the slight change in diet of the Diana monkeys upon forming these associations. The main benefit from these associations is protection from predators. The book Primate Behavioral Ecology states that, “when species associate, the one that alters its behavior while accompanying the other is the one that either benefits the most, or incurs higher costs from the association” (273). Since both species of monkeys alter their behavior slightly, it would imply that the monkeys receive equal benefits from their associations. According to an abstract I read, the red colobus monkey was primarily responsible for the initiation and maintenance of the associations. Though their weights are similar, it seems that the red colobus monkey is responsible for initiating associations.

 Work Cited:





Primate Behavioral Ecology: Karen Strier

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Week 13: How do We Access Cognition


Cognition in primates is measured in several different ways. The movie Ape Genius described several ways researchers measure cognition in primates. There were three experiments which really stood out to me: the experiment where the chimp needed help to pull the big box off of the food, the experiment where the bonobos needed to work together to pull the food into arms reach, and the experiment where the chimps were shown and imitated how to get the candy out of the box.

                In the experiment where the chimpanzee needed help from the researcher in order to get the food from under the box was informative in several ways. One of the most surprising aspects of watching that experiment was the chimpanzee’s recognition of what kind of help he needed and his ability to communicate with the researcher. The chimpanzee guiding the researcher to the handles he needed to pull and placing his hands there shows that the chimpanzee understands his limits keeping him from his food and has identified a solution that would allow him to reach his food. This experiment also shows the chimpanzee’s willingness to work with a human that he would be unlikely to show towards another chimpanzee. In contrast with chimpanzees’ unwillingness to work together, the experiment with the bonobos show the agreeableness in bonobos nature as well as their ability to understand to understand and complete their task of pulling the ropes in order to bring the food within their reach. This experiment shows that bonobos can learn these simple tasks through observations and rewards. The experiment which really shows the cognitive abilities of chimpanzees was the experiment with the box which dispensed candy. After the chimpanzees observed the experimenter doing various steps which led to dispense of candy, the chimpanzees were able to mirror her steps and enjoy their candy treat. Once the experimenter switched boxes to a clear box, she repeated the same steps to get to the candy. Instead of copying her steps, the chimpanzees only did the steps necessary to the acquisition of candy. This shows the cognitive ability chimpanzees have when it comes to solving problems. A major strength in this last experiment is that it shows that chimpanzees are able to identify the steps that keep them from the candy from the unnecessary steps and adapt their behavior accordingly.  This understanding is not surprising, given the abilities chimpanzees have shown in their creation of tools for hunting and the ways they have made hunting easier for themselves. Another strong point to this experiment is the ability for the other chimpanzees who had not been shown by the experimenter how to open the box to learn how to open it through watching the original chimpanzee open it. Chimpanzees from other, hostile groups were also able to get the candy through their observations of the original chimpanzee.

                Another experiment which I found interesting was the experiment where the chimpanzee was unable to overcome its greed in picking the larger number of treats that he knew would be given to the other chimpanzee. It was interesting how they compared that experiment with the experiment they did on children where the child had to sit in a room with one marsh mellow and not eat it. If the child resisted the temptation to eat the marsh mellow, they would be given two marsh mellows. The ability to resist the instant reward for the larger reward in the future was an ability that some of the children possessed while the chimpanzees were unable to overcome their choosing the larger number of treats even knowing that it would go to their neighbor. I think all of these experiments were important because they showed the depth of intelligence these primates have and their ability to use their intelligence to accomplish their task.

Photo from: http://news.nationalgeographic.com/news/2011/08/pictures/110805-rise-planet-apes-movie-science-chimps-gorillas-tools/ 

Week 12: Second Article Review


                For my article review, I am reviewing the article “Sex Differences in Play Among Western Lowland Gorilla (Gorilla gorilla gorilla) Infants: Implications for Adult Behavior and Social Structure” by Dario Maestripieri and Stephen Ross. As the title explains, this article discusses the differences in play between male and female infant gorillas and their preferences in types of play and with whom. This article goes on to explain why these differences occur and why they are so important.

                The results of their observations show that male infant gorillas engage in more play than females do, including solitary play and social play. Ross and Maestripieri explain this difference in play as suggesting, “that male immatures should practice their fighting skills through wrestle and chase play, and that their best training partners are likely to be other males” (Ross 58). Infant male gorillas learn how to fight and become a successful silverback gorilla through observing the behavior of their leader and through the skills they learned through play. Another observation made was the preference by both male and female infant gorillas to play with other male infants. The reasons for males to prefer playing with other males can be explained by the need to develop their skills. Ross and Maestripieri explain the females’ preference to play with male gorillas as being useful for teaching the young females the types of behaviors males enjoy in order to attract the best silverback later in life. Since the females usually migrate to new groups to find a silverback to mate with, the infant females don’t feel the need to form bonds with the other females in the group, as they will leave them in a few years anyway. Ross and Maestripieri also noted that play seemed to be a reciprocal action for gorillas; if an infant female were to initiate play with an infant male gorilla, he would be forced to initiate play with her at a different time.

                A strong aspect in this article was the detail the authors put into distinguishing the different types of play and when each type of play rose and fell. The authors noted that solitary play declined after the second year while social play increased into their third year, when it began to decline. Another strong point in the article was the observation of male infant gorillas were the only ones to initiate play with the adult females in the group who weren’t their mothers. The authors explained that infant male gorillas would initiate play with adult females to learn how to behave towards them for later in life. A third strong point of the article is the authors’ explanations towards the observations they present. The authors do a good job explaining what the observations mean and the significance of them. The one main weak point I saw in this article is the limited number of gorillas used for the observations. The authors only observed 12 gorillas. The limited number of gorillas could not be helped due to the limited number of infant gorillas in zoos in the US that would fit the requirements for the experiment.

                Overall, I think that the article was well written and I think that the observations made by the authors give valuable insight into the development of infant gorillas. I think it would be interesting to see if there are any differences in the play behavior of infant gorillas in the wild versus that of those in captivity. If I were to make a theory about this, I would theorize that the behavior patterns would be similar, except maybe the time the infant male gorillas spent playing would increase and there might be an even higher demand to play with other infant male gorillas. 

Work cited:

Maestripieri, Dario, and Stephen R. Ross. “Sex Differences in Play among Western Lowland Gorilla (Gorilla Gorilla Gorilla) Infants: Implications for Adult Behavior and Social Structure.” American Journal of Physical Anthropology 123.1 (2004): 52-61. Print.

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Week 11: Proposed Paper Topics

ImageFor my final paper, I will be discussing the behavior and development of infant and adolescent gorillas. I will be writing this paper in the literature review. I plan on discussing the differences in behavior and development between male and female gorillas. Through a paper I have already read, I learned that play is more important for young male gorillas than it is for females. When playing, both female and male infants prefer to play with male gorillas; males prefer playing with other male gorillas their age because it helps the gorillas develop proper motor skills and social bonds for later in life. Infant, female gorillas prefer playing with other infant male gorillas because it teaches them how to behave around and form bonds with males, which is very important for adult females (Ross 57). The results seen in the observations in this paper were not unexpected to me because of the behavior I have previously read about in Fossey’s book. When describing impish behavior made by a young gorilla, the troublemaker is usually a male attempting to either play or entertain himself. I also saw similar behavior at the zoo, but those observations aren’t valid due to the lack of immature female gorillas in the enclosure. The results of the observation in the same reading states that play is a reciprocal activity; if an infant gorilla initiates play with another gorilla, the gorilla with initiate play with the infant gorilla later on (Ross 56). Play is an important part in the development of infant and adolescent gorillas. Play teaches infant gorillas the skills that are vital for the survival of the gorillas later in life.

            An interesting behavior that I read about is that only male infants will initiate play with adult females other than their mother (Ross 58). This play will be helpful for the infant males as it teaches them the necessary behavior for interacting with adult females so that they may create their own group some day. The training that infant and adolescent males get through play is vital to the development of an adolescent male into a silverback. The behavior can be seen in Digit, who Fossey observed playing and wrestling with his siblings. By wrestling and playing, Digit learned the necessary motor skills needed to become an adequate silverback.

            A key question I plan on discussing in my paper is the differences in an infant gorilla and an adolescent gorilla and the development an infant must go through in order to be considered an adolescent gorilla. I also plan on discussing how developed an adolescent gorilla is compared to an adult gorilla both physically and mentally. According to an article in the American Journal of Primatology, “juveniles reach 90% of their potential brain mass by 28 months of age” (McFarlin 456). I plan on looking into the differences in development between female and male gorillas; I already know that play affects male and female gorillas differently and I am curious to see what else is different between the two. I do have some prior knowledge on the subject of infant gorillas as I researched them for my midterm paper, but there is much more that I can learn about them and I look forward to learning about them.

            I have found two papers that seem to be promising sources of information for my topic: “Early Brain Growth Cessation in Wild Virunga Mountain Gorillas”, written by several authors, and “Sex Differences in Play among Western Lowland Gorilla Infants: Implications for Adult Behavior and Social Structure” by Dario Maestripieri and Stephen Ross.

photo by http://www.theguardian.com/environment/gallery/2012/sep/24/orphan-baby-gorilla-centre-congo-in-pictures 

MCFARLIN, S. C., BARKS, S. K., TOCHERI, M. W., MASSEY, J. S., ERIKSEN, A. B., FAWCETT, K. A., STOINSKI, T. S., HOF, P. R., BROMAGE, T. G., MUDAKIKWA, A., CRANFIELD, M. R. and SHERWOOD, C. C. (2013), Early Brain Growth Cessation in Wild Virunga Mountain Gorillas (Gorilla beringei beringei). Am. J. Primatol., 75: 450–463. doi: 10.1002/ajp.22100

Maestripieri, Dario, and Stephen R. Ross. “Sex Differences in Play among Western Lowland Gorilla (Gorilla Gorilla Gorilla) Infants: Implications for Adult Behavior and Social Structure.” American Journal of Physical Anthropology 123.1 (2004): 52-61. Print.

Week 10: Zoo Impressions

ImageObserving the gorillas at the zoo was a unique experience for me. I was able to watch the gorillas almost undisturbed for two hours before families came to view the gorillas. The alone time I experienced with them allowed me to watch the behaviors of the gorillas without them being disturbed or bothered by small children or rude patrons. The quietness in which the gorilla spent their day was surprising for me, as I used to picture gorillas as being tough, loud creatures. The playfulness of the young gorillas was fun to watch, as they often came up with creative ways to entertain themselves. Being able to observe the gorillas in person different than I expected, mainly due to the size of their enclosure. I expected the gorillas to wander around their enclosure more but I also expected their enclosure size to be bigger. After reading Fossey’s book, I did expect the adult gorillas to spend the majority of their day lounging. A behavior that originally struck me as harsh was when Jamani would bite Apollo for playing with Bomassa. Jamani was very aggressive towards Apollo in these situations. Another surprising behavior was the neglect Olympia showed towards Apollo. While Apollo stayed fairly close to his mother, I rarely saw her play, groom, or pick up Apollo. This behavior was surprising given the protectiveness Fossey described in her book. It did appear that Olympia was suffering from some sort of ear ache, so that could be the reason behind her neglect. I noticed that the young gorillas would avoid Acacia and would run to their mothers if Acacia wandered close by. The loss of child suffered by Acacia might have resulted in her behaving badly towards the two young gorillas. I had looked forward to seeing an adult silverback in person and was saddened when I discovered that the silverback previously held there had recently died. I fear for the development of Apollo and Bomassa, as they no longer have an adult silverback to teach them how to mature and behave.

            While at the zoo, I was able to observe other primates, most noticeably being the chimpanzees. I was able to observe the chimpanzees for quick some time but I did not find them as interesting as I found the gorillas. I enjoyed observing the gorillas and would choose to observe them again given the chance. I found the gorillas to be the most enjoyable to watch due to the playful nature of the two young gorillas and the personalities of each gorilla in the exhibit. The chimpanzees were interesting to watch as they were a very active group, but I found them hard to keep track of and less enjoyable to watch. After observing the gorillas in their enclosure, I wish that they had more room to wander around. By forcing the gorillas into small enclosures so that they are easy to observe, the zoos are limiting the freedom gorillas usually enjoy in the wild. While it would be harder to observe the gorillas this way, I wish that the zoo built an enclosure similar to the enclosures of the rhinos and elephants, who had large ranges in which they could move around. The expanding of their enclosure could improve the quality of life for the gorillas at the zoo and could help give the gorillas a life closer to life they would have lived in the wild. I also believe that the zoo should do a better job monitoring the behaviors of those who visiting the zoo. While observing the baboons, a couple of adult males were behaving in ways that were provoking the dominant male baboon, causing him to become angry and jump at the patrons, hitting the glass and possibly hurting himself. For the animals at the zoo to live a better life, the zoo needs to protect their animals from the negative behaviors ignorant people do to provoke the animals.