Malayan words "orang
|Scientific name: Pongo pygmaeus|
|Range: Found on the Malaysian islands of Borneo and Sumatra in Southeast Asia; although range once extended into northwest India, China, Java, and Sulawesi.|
|Habitat: Live in lowland and hilly tropical rain forest, including dipterocarp and peat-swamp forest. Their habitat is almost wholly arboreal (tree dwelling).|
|Status: Endangered. Threatened by the destruction of its forest environment to make room for farms and villages, and to harvest lumber.|
|Diet in the wild: Orangutans are omnivorous; they eat both plants and animals such as: fruit, leaves, flowers, bark, nuts, shoots, insects, bird eggs, and small mammals. Some may be seen eating soil, a source of minerals for many animals. Water is drunk from tree holes by dipping in a hand and sucking the water-drops that fall from its wrist.|
|Diet in the zoo: Fruits such as apples, oranges, bananas, and kiwi, in addition to vegetables like carrots, yams, and romaine lettuce.|
Second in size only to the gorilla, the orangutan male weighs 130-220 lbs; whereas, the female is about 88-110 lbs. Height, males are 4 to 5 ft and females 3 1/2 ft. Characterized by long, shaggy, reddish-brown hair that can reach 20 inches. Bare face, with round eyes and small ears. Short, weak legs and long, powerful arms, curled fingers and feet, flexible shoulder and hip joints. Size usually determines the orangutan's sex since males are always much bigger. In addition, males develop large fleshy flaps (cheek pads) on faces, and large throat pouches. Males also possess pouches of pebbly skin on chest.
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.
physiological or behavioral
ANATOMY: They have a truly opposable thumb, so that the forefeet are really like hands. This inter digital grip allows them to pick fruit or grasp slender branches. The big toe is also opposable. Their cheek pads act as megaphones to project "long calls," which sounds like a loud roar. In addition, the pendulous laryngeal sac, when inflated, increases the resonant tone of the voice.
SENSES: Excellent binocular vision.
LOCOMOTION: Orangutans move through the trees by "brachiating," or hooking their long fingers over branches and swinging by their arms. Their ability to brachiate and even hang upside-down enables them to retrieve fruit. When on the ground, they walk on all four limbs, using the knuckle pads on the back of the digits on the hands.
BEHAVIOR: Less social than the other apes. Mature males appear to be totally intolerant of each other. They tend to be quiet, relatively shy and spend most of the day eating and resting.
INTELLIGENCE: Highly. They can solve problems related to arboreal travel and food processing, trained to perform tricks and communicate with sign language to ask for items of interest, such as food and contact.
|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.|
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
Michael, R., 1973, Comparative Ecology and Behavior of Primates, Academic Press, London pp 42-45.
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