Orangutan Life Stages

On this second day of #orangutancaringweek I’ll explain more about the life stages of orangutans.

Orangutans are the largest arboreal animals in the world and spend over 95% of their time in the trees. They are also among the most sexually dimorphic of primates with males much larger than females. Fully developed adult males can weigh up to 21 stone, while adult females weigh less than half that weight. Adult male orangutans can reach a height of five feet and can have eight foot arm spans. Whilst their long arms and legs mean they can move easily through the tree canopy, their weight can result in branch breakages. Although smaller, younger orangutans move almost silently through the forest, the same cannot be said for large males!

Males can attain sexual maturity in their teens, but may not attain full size until they are in their twenties. On maturity, males develop large cheek pads called flanges and also large throat sacs. These are a sign of dominance and are found attractive by female orangutans. The presence of a dominant cheek-padded male within the range of younger adult males may inhibit their development.

Females become sexually mature when fully grown, although they will not have their first offspring until 15 to 16 years of age in the wild. The female’s menstrual cycle is similar to our own, occurring every 29 to 32 days with menstruation lasting three to four days. After successful mating, the female is pregnant for approximately eight and a half months before giving birth.

Usually a single offspring is born, weighing about 3½ pounds. Orangutan babies are completely dependent on their mother, and youngsters stay close to their mother until they reach adolescence, with orangutans having the longest “infancy” of the great apes. The bond between a mother and their infant is very strong.

In the wild, females will not mate and give birth again until their offspring is independent. At Tanjung Putting, where supplementary feeding is given, females are often seen with two youngsters – a young baby and an adolescent that is not yet independent.

Almost from birth, orangutans have a very strong grip, which is necessary for the youngster to hang on to their mother as they move through the tree canopy. Even at the relative safety of the feeding stations, older youngsters often keep at least one limb firmly gripped onto their mothers fur, their proximity reassuring and offering them safety and a quick escape from other adults, should this be necessary

To learn more about orangutans, visit
https://www.orangutan.org.uk/orangutans

#orangutans #redape