Green Orangutan

Green Orangutan

Habitat: Haulout Island; River Forest
Type: Arboreal Primate
Height: 4 to 5.5 Feet (standing)
Weight: 120 to 250 Pounds

Adult Male, Female, And Their Young

The Green Orangutan is the largest animal living in the River Forest. It is an excellent climber and spends most of its time moving easily through the tree branches. Even the largest individuals are still nimble and are not limited in their climbing by their size.

They live in small family groups, typically made up of one adult male, several adult females, and their young. These groups stay close together and individuals do not range far from one another. Nighttime is spent in a constructed nest, with a unique nest for each adult in the group. They return to the same nests each night, and a new one is not constructed unless the first is destroyed or damaged somehow.

The Green Orangutan is not naturally green. Its skin is gray and its hair is actually light blonde. But over time algae grows throughout the hair and changes its color. Young individuals are born pale and receive their green tint as they get older. The older an adult gets, the darker green it becomes. In the thicker parts of the forest, this makes them difficult to see when they are not moving.

Mother And Baby Feeding As Blue
Ground Hawk Walks By

Most feeding takes place in the trees. Fruit makes up the majority of their diet, and they will remain in a single tree while feeding until it is picked clean of its fruit. They will also eat other food whenever it becomes available, including bird eggs and small animals. Young Greater Gliders, Giant Tree Squirrels, and Fox Lemurs are eagerly taken whenever they have a chance, adding some meat to their usual diet.

They are rarely found on the ground, usually only coming down from the trees to drink. These visits are brief, and the group remains at high alert while on the ground. Most predation occurs during these times, typically from the Blue Ground Hawk. Smaller individuals are especially at risk from these birds. While the adults will usually try to defend them, there is not much they can do to ward off a pack of these predators. 

Old Adult Male, Showing Darker
Coloring And Wide-set Face

Even adult males are at risk when coming to the water’s edge, as juvenile Lake Dragons (still up to twenty feet long) will attack from below. Once seized, escape for the Orangutan is unlikely.

• Naturalist Note: The Green Orangutan corresponds closely to the extinct ape Sivapithecus, a primate widely regarded as closely related to modern orangutans (Pongo). Daniel’s observations of body size, arboreal locomotion, and social structure are broadly consistent with what would be expected of a large, canopy-adapted great ape like Sivapithecus.
  
  The observation of the green coloration as a form of algal growth is noteworthy. This symbiosis has been well-documented in modern mammals—most notably sloths—and appears here to have developed to a much greater extent. It is even possible that this particular algae is found only in the coats of these apes.
  
  Predation pressures described by Daniel are significant and help explain several behavioral traits. The reluctance to descend from the canopy, the tight grouping of individuals, and the speed of ground visits all reflect adaptation to a landscape where even large primates are vulnerable. The flightless, predatory birds called Ground Hawks are likely some type of phorusrhacid "terror bird." The Lake Dragon, as described in other writings, appears to be a type of predatory ichthyosaur, possibly Cymbospondylus.