Chimpanzee Cannabalism And Infanticide Essay Research Paper

Chimpanzee Cannabalism And Infanticide Essay, Research Paper

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The acts of cannibalism and infanticide are very apparent in the behavior of the chimpanzee. Many African studies show that wild chimpanzees kill and eat infants of their own species. (Goodall, 1986:151) Although there is not a clear answer why chimps engage in this very violent and sometimes gruesome behavior there are many ideas and suggestions. This essay will deal with chimpanzee aggression, cannibalism and infanticide. This paper will present information on major research studies performed in Africa and analyze how and why this strange behavior occurs in a commonly thought peaceful primate.

Wild chimpanzees(Pan troglodytes schweinfurthii) are known to kill and eat mammals in various parts of Africa. Monkeys were recorded to be consumed in the Gombe National Park, the Kasakati Basin, and the Budongo Forest. Moreover, there is new evidence that chimpanzees near the Ugalla River of western Tanzania also consume mammals.(Riss, 1990:167) Cannibalism has also been recorded both in the Budongo Forest, Mahale Mountains and the Gombe National Park.

In Jane Goodall’s, May 1979 article in the National Geographic called “Life and Death at Gombe” it reveals the first time that chimpanzees who were always perceived to be playful, gentle monkeys, could suddenly become dangerous killers. “I knew that some of our chimpanzees, so gentle for the most part, could on occasion become savage killers, ruthless cannibals, and that they had their own form of primitive warfare.”(Goodall, 1979:594) To try and explain this ruthless behavior it is necessary to first analyze their social upbringing and unique lifestyle.

The Chimpanzee society is clearly a male dominated aggressive social unit. Males are larger than females, they are more openly aggressive, and they fight more often. (Holloway, 1974:261)

These fights can look extremely fierce and

the victim screams loudly. But it is rare

for a fight between community members to last

longer than quarter of a minute, and it is

even more unusual for such a fight to result

in serious injury.(Goodall, 1992:7)

Many fights break out suddenly. Afterwards the loser of the fight, even though clearly fearful of the aggressor, will almost always approach him and adopt a submissive posture.(Goodall, 1992:8) The loser is giving in and admitting that he has lost and only feels relaxed when the aggressor reaches out and gives what is called a “reassurance gesture-he will touch, pat, kiss or embrace the supplicator (loser).”(Goodall, 1992:8)

Another example of chimpanzee aggression is the charging display. Although females sometimes display this behavior, especially high ranking, confident females, it is typically a male performance.(Reynolds, 1967:82) During such a display, the chimp charges flat out across the ground, slapping his hands, and stamping his feet. The chimps hair then begins to bristle and his lips bunch in a ferocious scowl. He may pitch rocks or jump around swinging branches.(Strier, 1992:46) Essentially what he is doing is making himself look bigger and more dangerous than he actually is, trying to intimidate his opponents. “We have found, over thirty years of study, that the young males who display the most frequently, the most impressively, and with the most imagination, are the most likely to rise quickly to a high position in the male dominance hierarchy.”(Goodall, 1992:9)

In essence, every young male chimp is on a life long quest to become the top-ranking position of the male hierarchy that is called the “alpha-male.” Many of the male chimpanzees spend a lot of energy and run risks of serious injury in pursuit of higher status. The rewards of the alpha male are claiming rights to the food, female partners, and he also acquires a position exempt from attack by fellow chimps.(Goodall, 1979:616) However, the latter discussion has dealt solely with inter-group aggression, (fighting within groups of the same community); outer-group aggression is grotesquely different.

A chimpanzee community has a home range within which its members constantly roam. Usually the home range consists of roughly five to eight square miles. The adult male chimpanzees usually in groups of three, take turns patrolling the boundaries of their area keeping close together, silent and alert.(Goodall, 1992:14) As they travel they pick up objects sniffing them as if they are trying to find clues to locate strangers. If a patrol meets up with a group from another community, both sides usually engage in threats, and then are likely to retreat back to their home ground.(Holloway, 1974:261) But if a single individual is encountered, or a mother and a child, then the patrolling males usually chase and, if they can, attack the stranger.(Goodall, 1979:599) “Ten very serious attacks on mothers or old females of neighboring communities have been recorded in Gombe since 1970; twice the infants of the victims were killed; one other infant died from wounds.”(Goodall, 1979:599)

In 1972 the chimpanzees of Gombe divided into two groups: the southern group(Kahama)and the northern group(Kasakela). This was the start of what Jane Goodall called the “four year war.” In 1974, a gang of five chimpanzees from the Kasakela community caught a single male of the Kahama group. They hit, kicked, and bit him for twenty minutes and left him bleeding from many serious wounds. A month later after this original occurrence another prime Kahama male was caught by three chimps from Kasakela and severely beaten. A few weeks later he was found, terribly thin and with a deep unhealed gash in his thigh. There were three more brutal attacks leaving three more Kahama chimpanzees dead before 1977.(Goodall, 1979:606) By 1978 the northern males had killed all of the southern group and took over both areas. “It seems that we have been observing a phenomenon rarely recorded in field studies-the gradual extermination of one group of animals by another, stronger, group.”(Goodall, 1979:608) There is no clear reason for these brutal attacks to have taken place unless that the dominant northern males before the community split, had access to the southern community and they were just trying to attain their land back. “We know, today, that chimpanzees can be aggressively territorial.”(Goodall, 1992:14)

In August of 1975, Gilka a chimpanzee mother was sitting with her infant when suddenly Passion, another mother appeared and chased her. Gilka ran screaming but Passion who was bigger and stronger caught up, attacked, seized, and killed the baby. She then proceeded to eat the flesh of the infant and share the gruesome remains with her adolescent daughter, Pom and her infant son, Prof. This was the first observed instance of cannibalistic behavior shown by Passion and Pom.(Goodall, 1992:22) About a year after this incident, Gilka gave birth to another infant and this time it was Pom who seized the baby, but Passion and Prof again shared the flesh. There is no explanation why Passion and Pom behaved as they did.(Goodall, 1992:23)

Passion was always an asocial female, and

had been a very harsh mother to her own first

infant, Pom. It was only as Pom grew older