Malayan words "orang
utan"mean "forest
man"
General information:
The orangutan is the largest fruit-eating animal
on earth. An estimated 30,000 are still left in the wild. They are diurnal
(active during the day), peaceable, gentle and friendly towards man when
unmolested. Unlike the gorillas and chimpanzees, the orangutans have a
semi-solitary social system that evolved as a result of food distribution, and
a lack of predators in the wild. These animals are graceful and efficient in trees; however, they appear awkward on the ground because they lack balance. As a result of their deficiency in balance, they walk on the palms of their hands similar to how human infants crawl. This quadrupedal locomotion hinders them from traveling fast and for long periods of time. Orangutans engage in human like activities like face-to-face copulation, comprehension of speech, tool manufacturing, and imitation. Orangutans are similar to gorillas in the area of intelligence and communication due to their common ancestry. Life Cycle: There is only a brief period of courtship during the breeding season. Males are not successful in attracting sexually receptive females until they receive their cheek pads. Between the ages of 10 and 15 the males resort to rape if females are not receptive. These rapes usually last 10 minutes, but in captivity these rapes vary in time. Females in captivity are more likely to adapt to their mates. Normally, a single young is born after an 8.5 month gestation, weighing an average of 3.25 lbs. During the first year, an infant clings to its mother's abdomen and is nursed frequently. The infant is fed pre-chewed food. Mothers do not conceive while nursing. It takes 10-12 years for an orangutan to reach full growth. In captivity, they live to more than 50 years; in the wild, they live to about 35 years. |
Comments about the
orangutans of the Fort Worth Zoo. The current orangutans are from Indonesia. The adult male (whose name means "Sir" in Indonesian) is a pure bred Sumatran orangutan; he is the father of two infants, one ("imagination") who is 8 yrs. old and another ("patience") who is 4 1/2 yrs. old. The Sumatran female ("pretty") is the mother of these two youngsters. Surprisingly, the primates' keeper stated that the zoo has two hybrid orangutans: a 22 yrs. old female who is the mother of a young male 11 yrs. old. For more clarification, a hybrid orangutan's DNA is the makeup of both a Bornean and Sumatran orangutan's genes. Male orangutans are less aggressive to each other since they have adapted to living in captivity. In fact, the males at the zoo are very good with infants; whereas, in the wild they neglect them. Research has shown that a double male group, which describe males living in close proximity, tends to retard secondary sex characteristics (or cheek pads) on young males. The slow development of cheek pads keep them younger and less aggressive. Their cheek pads also act as megaphones to shoot "long calls" further. A "long call" is described as a grumbling sound a male makes to announce his presence. |
Personal Observations: The orangutans did not appear active at the zoo. Some were resting on the wooden apparatus while surprisingly, others were on the ground resting in a group. Orangutans rarely step foot on the ground in the wild; however, in captivity they do not have trees to climb upon. Since these animals are used to living in captivity, they were not excited to see people or to mimic people's gestures. The male and female orangutans at the zoo were not big in size. In fact, only one male had really developed cheek pads. |
Current research:
Pittsburgh Zoo - Research - http://keyselections.lm.com/orangutan_reconciliation.html Orangutan Species Survival Plan - http://www.aza.org/aza/ssp/orangtnAR.html Orangutan Page - http://www.tourismindonesia.com/orang.htm Primates - http://www-bcf.usc.edu/~aalonso/Academic/primate.html |
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Source of
information: BOOK: Michael, R., 1973, Comparative Ecology and Behavior of Primates, Academic Press, London pp 42-45. INTERVIEW: Linda Roberts, Primates Zoo Keeper April 1998, Fort Worth Zoo (817) 871-7050 Building 7087 INTERNET WEB SITES: http://www.whozoo.org/mammals/Primates/orangs.htm for orangutan pictures http://www.ns.net/orangutan/facts.html for orangutan holding a book picture and drawing http://www.primate.wisc.edu/pin/factsheets/links.html#pongofor Primate Information Net Links to Orangutans http://www.birminghamzoo.com/ao/mammal/orang.htmfor Animal Omnibus Page at the Birmingham Zoo http://arkive.uwe.ac.uk/species/Orang_Utan.html for ARKive Page http://cisunix.crcssb.edu.on.ca:1080/~tho/orang.html for Endangered Species Page http://www.bagheera.com/clasroom/casestud/orang.htm for Orangutan Page |
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