Orangutans :: essays research papers

Orangutans In Malay orang means "person" and utan is defined as "forest'. Thus Orangutan literally means "Person of the Forest". Orangutans are found in the tropical forests of Sumatra and Borneo. They are the most arboreal of the great apes and move amongst the safety of the trees from one feeding site to the next. They are so well adapted to arboreal life that they cannot place their feet on the ground, instead they walk on the outside of their curved foot. There is a scattered population of orangutan in Indonesian Borneo, Malaysia Borneo and northern Sumatra. The different habitats have isolated the orangutan reproductively and geographically from one another creating a "degree of difference" or two subspecies. There are several different characteristics between the two subspecies of orangutans and it has recently been suggested that they may be a separate species. The Borneo male has relatively large cheek pads, a tremendous laryngeal sac and a square shaped face. The Sumatran male has small pads and laryngeal sac, a ginger coloured moustache, a pronounced beard, and a diamond shaped face. Individuals can also be distinguished chromosomally, biochemically, and by their cranial characteristics. There is a great deal of individual variety in the orangutan. "Each orang-utan had a distinct personality and in dealing with such highly intelligent animals in captivity, the keeper's knowledge of the individual was probably more important than the knowledge of the overall behaviour patterns " (Markham, 1980). Orangutan males, however, appear to be totally intolerant of one another, especially the Borneo males who are even aggressive towards females and infants. Male orangutans' participation in social groups is limited to sexual "consortship" with females. However, the Sumatran males tend to stay with females for a longer period of time usually until the birth of the infant. They may stay longer with their partner because of the presence of large predators absent in the Borneo habitat. The orangutan has a menstrual cycle of 29-30 days, menstruation lasting 3-4 days. The Gestation period lasts slightly less than nine months. Offspring pass through three stages, infancy (0-4), juvenile (4-7), and adolescents (7-10). Mother young relationship lasts for a long time, the young usually stay with their mother until they are mature. Female Orangutans are not sexually mature or fully grown until the age of twelve and will not have their first offspring until they are at least fourteen. Males become sexually mature and fully grown at the age of fifteen. The cheek flanges of the male easily recognize the differences between adults and semi-adults. The flanges in the Boreal male curve out ward from the face and develop around the