Even where they’re numerous, seeing a wild orangutan takes a bit of luck. The rainforest is dense and the orangutans keep mainly to the trees. Sure, there are forest fragments and national parks where orangutans are more reliably viewed, but in much of their habitat they’re a rare sighting.
Last year, I visited East Kalimantan in Borneo as a trip to see conservation that benefits orangutans and other species. It is part of a partnership between TNC, Indonesian conservation organization YKAN and furniture brand Arhaus.
A critical part of effective conservation is utilizing science to direct the work and then monitoring its effectiveness. But how do you monitor a tree-dwelling, elusive species? Fortunately, researchers utilize the latest technology to help in researching orangutans.
Orangutans will use the ground to move about, a rare sight for someone walking through the forest but captured on camera traps. Here is a collection of images from the Wehea Protection Forest, consisting of 29,000 acres of protected by the Dayak Wehea Community. The partnership with Arhaus will protect similar forest allotments with community-led conservation.
Orangutans spend most of their time in trees, but will come to the ground for a variety of reasons, including water. This photo shows an older male, distinguished by its large, fat-filled cheek patches called flanges.
Females prefer to mate with these dominant males. When males age and lose dominance, they also lose the fat in their cheek pads. This is unique among apes. A big male can weigh nearly 200 pounds, nearly twice that of females.
Males can grow so heavy that moving between trees becomes difficult, so they move about on the ground.
Orangutans can live in secondary forest or logged areas, but this increases the potential for human-orangutan conflict and puts the orangutans at risk for poaching. Healthy, connected forest are necessary for orangutans to thrive.
Young orangutans typically stay attached (literally) to their mothers until they’re two years old. They will follow closely for the next several years, then begin exploring away from the mother. At age 7 or 8, they become independent.
Orangutans feed primarily on ripe fruit but will also consume figs, leaves, palm hearts and bark. There are even records of them eating bird eggs, small mammals and even other primates when the opportunity presents itself.
Camera traps provide evidence of orangutans using an area. The time-tested method of assessing orangutan populations is by counting their nests. Orangutans build a nest each night, a skill that they pass on to young. They carefully use branches and leaves to build a nest that will support their weight.
Nests are concrete evidence of orangutan presence. Counting nests can give an estimate of orangutan populations. Researchers can conduct them on a grid on the ground, which is grueling, or using aerial surveys via helicopter or drone.
Kalimantan in East Borneo is a stronghold for orangutan populations, but the animals face threats from habitat conversion and poaching. A recent study found 78 percent of Kalimantan’s orangutans were found around villages outside protected areas – making community-led conservation paramount in saving this species.
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