Chimpanzee

This essay has a total of 2301 words and 10 pages.

Chimpanzee

Chimpanzee


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
that the very close bond developed between
mother and daughter, and it was only because
the two acted with such perfect co-operation
that they were able to overcome some of the
other females of their community.(Goodall, 1992:23) During the years
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