Difference of Aggressive and Submissive Behaviors between Chimpanzees and L'hoest Monkeys - Assignment Example

Behavioral Differences between Chimpanzees and lHoest Monkeys Primates exhibit a wide variety of behavioural traits. Aggressive and submissive behaviours can be found among all species in the animal kingdom. Seeking to understand the particular behavioral differences between Chimpanzees and lHoest Monkeys, this study addresses both aggressive and submissive behaviour in these two primates. INTRODUCTION Aggression is an important behaviour exhibited by animals in the wild. Aggressive behaviour can ward off threat by predators, protect kin and kind and be employed in the hunt for prey. Thus aggression can serve a variety of important purposes in the animal kingdom. Submissive behaviour on the other hand, can be dangerous for primates who operate in a no-holds-barred “dog-eat-dog” world. Submissive animals are more likely to hunted, less able to defend themselves and their offspring and more quickly likely to become prey. Is there a biological basis for certain types of behavioural traits in animals? Are some primates more aggressive than others? Animal behaviour has always been addressed by zoologists. Studies from the Colchester zoo have addressed a variety of behavioural traits among primates. In her study entitled, “The effect of a foraging enrichment on the behaviour of buffy-headed capuchin monkeys”, Amanda Skornia observed primate behaviour for six days and discovered positive behavioural differences in buffy-headed capuchin monkeys following enclosed environmental enrichment (Skornia 2002). In a study of aggression in captive patas monkey, Donna Miller observed the behaviour of this primate following a collective move to a new enclosure. Overall activity and aggressive behaviour was observed following the move but a direct correlation between the actual aggression and the move could not be adequately established (Miller 2002). Although not a primate-specific study, in her insightful analysis of behaviour among lions, Hayley Monaghan looked at different behavioural traits between zoo lions and safari lions (2002). She undertook this study on the effects of captivity and determined that there is a significant difference between activity levels of lions in the zoo and in safari parks. The active behaviour of male and female lions was significantly higher in the zoo than in the safari. As we shall see in the Discussion section of this essay, the Monaghan study, although not directly tied to primate behaviour, will have important implications for future research on behavioral differences between chimpanzees and lHoest primates. The particular behaviours of chimpanzees and lHoest monkeys have been addressed for decades in the literature. In a fascinating article entitled, “Recent developments in the study of wild chimpanzee behavior” Mitani, Watts and Muller studied wild chimpanzee behaviour in Kibale National Park, Uganda. Observing chimpanzees in the wild, they studied the effects of age and social rank on male chimpanzee behaviour, territorial aggression and inter-group aggression. Accordingly, it was determined that aggression was an important aspect of chimpanzee behaviour in the wild (Mitani, Watts and Muller 2002; Mitani and Watts 1999). In a particularly relevant comparative study published in the International Journal of Primatology, the behaviour of lHoest monkeys was contrasted with that of blue monkeys in Nyungwe Forest Reserve, Rwanda. While under observation, the diet of l’Hoest monkeys was determined to be largely terrestrial herb-based, then followed by seeds (Kaplin 2001). Aggressive behaviour was not sufficiently discovered among l’Hoest monkeys as their diet did not force them to engage in a predatory nature (Kaplin 2001). In undertaking my analysis, I hypothesize that as the “closest living relatives” to humans (Mitani, Watts, Muller 2002), chimpanzees will display more versatile behaviour and there will be a difference in the behaviour of chimpanzees and lHoest monkeys. This hypothesis is non-directional and it is two-sided. While this hypothesis was informed by each study mentioned in the literature review above, the observations by Mitani, Watts and Muller (2002) regarding chimpanzee behaviour in Kibale National Park, Uganda were particularly fruitful for this analysis. Additionally, Kaplin’s comparative study (2001) on the dietary behaviour of lHoest monkeys in Nyungwe Forest Reserve, Rwanda had a direct impact on the formulation of this hypothesis. Regarding aims and research methods, the observational technique used in this study was borrowed from Amanda Skornia and Donna Miller, who each used observation as a primary research tool in their respective analyses. The behavioural traits of chimpanzees and lHoest Monkeys is the focus of this study because there is dearth of comparative information on the subject of primate aggression and submission in the literature. RESULTS Assessing behavioral differences between chimpanzees and lHoest monkeys through observation, the terms “aggressive behaviour” and “submissive behaviour” were defined to provide a theoretical basis to the analysis. Aggressive behaviour was defined and observed as the following: biting, kicking, punching, showing teeth, pushing, throwing, chasing, and fighting. Submissive behaviour was observed as the following actions: play fighting, grooming, play individual, play group, sleeping, protecting and finally, feeding. Firstly, I observed five different groups of primates at my local zoo for five minutes each and then chose the two most active groups: the l’Hoest monkeys and chimpanzees. I studied each group twice for thrity minutes, once before lunch and once after lunch. Of note, the gender of the sample was not known or the ages of either group or the hierarchical system. Accordingly, the chimp enclosure had a youngster who was extremely lively and may have had an impact on the results. Both chimps and l’Hoest monkeys were quieter after lunch. Aggressive Behaviors Submissive Behaviors These results were obtained through the observation method, the most practical way to observe both aggressive and submissive behaviour of these primates. They are displayed in a bar graph because this method is an excellent way to display nominal data while making it very easy and clear to understand the difference between the primates being studied. Whilst aggressive behaviours seemed to be roughly evenly distributed across the two primates (with the exception of a lot of aggressive chasing coming from the l’hoest monkeys), the submissive graph tells a different story, with the chimpanzees performing a much higher number of submissive acts such as playing, feeding and cuddling. Influential statistics included play fighting, play group, sleeping, feeding, running and cuddling columns in the Submissive Behaviour graph. On the other pushing, fighting and throwing were influential columns on the Aggressive Behaviour graph. A chi-square model was used as it is the most widely used theoretical probability distribution model and useful for numeric data. A goodness of fit test is also a useful method to compare and contrast the documented behaviour under analysis. The primates were randomly drawn from the population sample and behaviour was observed in raw counts of frequency. With a level of significance of p=0.05 and a critical value of 3.84, our non-directional hypothesis was accepted: There were differences in the behaviour of both sample populations with chimpanzees displaying more versatile behaviour than lHoest monkeys. DISCUSSION & CONCLUSION As “one the best and most-widely studied non-human primates”, chimpanzees were an exciting primate to document. Accordingly, important differences in aggression could not be established using the chi-square distribution model, chimpanzees performed a much higher level of submissive acts, thus contributing to more overall versatile behaviour. These results were expected and affirmed the hypothesis of this study. The lHoest monkeys displayed surprisingly high aggressive behaviour, something not necessarily expected in the study. The aim of observing differences in aggressive and submissive behaviour was established using the observation method, an excellent way to gage these behavioural traits in primates. Background research informed and helped confirm the hypothesis of this study: there were important differences in the behaviour of both sample populations with chimpanzees displaying more versatile behaviour than the lHoest monkeys. The research undertaken by Mitani, Watts and Muller (2002) regarding the aggressive behaviour of wild chimpanzees in Kibale National Park, Uganda played an important role in the formulation of this thesis. Results undertaken in my study confirmed the published results of these researchers. Additionally, research on the diet of the l’Hoest monkeys by Kaplin (2001) informed my expectations for the behaviour of the l’Hoest monkeys. Importantly, extrapolations from the research undertaken by Kaplin led me to a different conclusion than the one reached in my analysis regarding the aggressive tendencies of the l’Hoest monkey. While providing an excellent basis for further research into the study of primate aggression, my study was hindered by a few limitations. Firstly, it did not distinguish between male and female behaviour within the two sample population groups. Additionally, the inclusion of a young chimpanzee among the chimpanzee group (there were no young individuals in the lHoest primate group) may have skewed results in favor of increased activity of this primate group. Finally, my study dealt exclusively with primate behaviour in captivity. Future research should focus on an extrapolation of the comparative approach utilized in this study and borrowed from Monaghan (2002) in her analysis of comparative lion behaviour. Accordingly, differences in behaviour between primates in the wild and primates in captivity needs to be taken into account with an understanding that environmental factors will have a significant influence on behaviour. Additionally, further research should look at longer periods of observation as well as perhaps focus on more specific primate behaviours. Despite these constraints, this study of primate aggressive and submissive behaviour has provided an excellent basis for further research into the comparative study of primate aggression. REFERENCES Kaplin, B.A. (2001). Ranging Behavior of Two Species of Guenons (Cercopithecus lhoesti and C. mitis doggetti) in the Nyungwe Forest Reserve, Rwanda. Journal International Journal of Primatology 22, 521-548. Mitani, J.C., Watts, D.C. (1999) Demographic influences on the hunting behavior of chimpanzees American Journal of Physical Anthropology, 109:4, 439 – 454. Mitani, J.C.,Watts, D.P., Muller J.C. (2002). Recent developments in the study of wild chimpanzee behavior. Evolutionary Anthropology, 11:1, 9 – 25. Miller, D. (2002). A study of captive patas monkeys. Colchester Zoo. Last Accesessed August 13 2008 Monaghan, Hayley (2002). The difference in activity behaviours between zoo and safari kept African lions (Panthera leo). Colchester Zoo. Last Accesessed August 16 2008 Skornia, Amanda (2002). The effect of a foraging enrichment on the behaviour of buffy-headed capuchin monkeys. Colchester Zoo. Last Accesessed August 23 2008 Read More