Orangutan
The orangutans are two species of great apes known for their intelligence
Size
Females can grow to around 4 ft 2 in or 127 centimetres and weigh around 100 lbs or 45 kg, while flanged adult males can reach 5 ft 9 in or 175 centimetres in height and weigh over 260 lbs or 118 kg.
Feeding
Orangutans primarily eat fruit, along with young leaves, bark, flowers, honey, insects, and vines. One of their preferred foods is the fruit of the durian tree, which tastes somewhat like sweet, cheesy, garlic custard. They discard the skin, eat the flesh, and spit out the seeds. In some regions, orangutans also occasionally eat soil, thus ingesting minerals that perhaps neutralize the high quantities of toxic tannins and acids in their vegetarian diet.
Behavior
Orangutans are diurnal animals, spending a large portion of daylight hours searching for and consuming food. Most of their lives are spent in trees where they travel from branch to branch by climbing, clambering, and brachiating. Usually each night, a new nest for sleeping is constructed from branches and built 15 to 100 feet up in a tree. Although mostly arboreal, males will occasionally come to the ground to move between stands of trees. While females stay near their mothers’ home ranges, males emigrate long distances. This helps minimize inbreeding within populations.
In the wild, orangutans have been observed making simple tools to scratch themselves. They also use leafy branches to shelter themselves from rain and sun, and sometimes even drape large leaves over themselves like a poncho. They have also been observed using branches as tools during insect foraging, honey collection, and protection against bees, and to fish for branches or fruit that is out of reach.
Adult male orangutans usually keep a considerable distance between one another; their participation in social groups is usually limited to temporary sexual "consortships" with adult and adolescent females. Adult females may be seen with their young, with adult females, and with adolescents who are not necessarily their own. The mother-young relationship lasts for many years, whereas the time spent with non-related orangutans is relatively short. Sub-adult males usually associate with females. Adolescent females travel together when age differences are minimal. This semi-solitary social system may have evolved as a result of the scattered food distribution and a lack of large predators.
Whereas the female orangutan can often remain sexually passive, a male must pursue his reproductive interest, using his pendulous laryngeal sac for the "long call," parts of which sound like a loud roar. The male orangutan’s call plays an important role in repelling male rivals and advertising his availability to sexually receptive females, helping him to compete aggressively with other adult males. Thus, mature male orangutans appear to be intolerant of each other, and the meeting of two mature males usually results in either aggression or avoidance.
Breeding
Females become sexually mature when fully grown, although they will not have their first offspring until 13 to 16 years of age in the wild. Males may attain sexual maturity in their teens, but their cheek pads may not become fully-developed until they are in their twenties since the presence of a dominant cheek-padded male within the sensory range of a younger adult male may inhibit the younger orangutan’s development. Generally, males are not successful in attracting sexually receptive females until they get their cheek pads. Thus, as sub-adults, the males frequently resort to "forceful copulation."
The female orangutan’s menstrual cycle is 29 to 32 days, with menstruation lasting three to four days. The gestation period is approximately eight months. Usually a single offspring is born, weighing about 3 ½ pounds. The young stay close to their mothers until they reach adolescence. Orangutans have the longest "childhood" of the great apes
