Orangutans are human-like apes, known for their distinctive reddish-brown hair. Called the “man of the forest” in Malay, their populations are critically endangered. The illusive and beautiful creatures tend to live solitary existences, preferring to be alone rather than in large social groups. They are chiefly herbivores, subsisting on wild fruits like figs, mangosteens, and lychees. There are two main populations of orangutans in the wild: Bornean and Sumatran. These two groups differ in appearance and behavior. The Bornean subset have longer facial hair, while Sumatrans are less solitary and tend to have more social bonds. Surprisingly, Bornean orangutans, although measuring less in population size (7,000), are more genetically diverse than Sumatran orangutans (50,000). Both populations face mounting threats at the hands of loggers and poachers.
Orangutans have experienced marked environmental destruction and population decline over the past 20 years, with a reduction of at least 55% in all. Bornean orangutans, in particular, have been negatively affected by commercial logging and deforestation, creating devastating territory fragmentation. When large swaths of habitat are transformed into smaller, unconnected patches, orangutans become unable to find adequate shelter, food, and mates. Only 1,500 orangutans remain in Northwest Borneo, making this subspecies one of the most endangered groups in the wild. Environmental agencies recommend that governmental bodies partner with logging companies, and other commercial interests, to raise public awareness for the plight of orangutans to curb this decline.
Interestingly, many scientists say that while deforestation is a major source of population decline for Bornean orangutans, hunting may be an even bigger problem. Studies show that many orangutans have disappeared from intact forests, suggesting that poachers are killing them for their beautiful red hair, and as black market prizes. There is a prolific black market of orangutan babies around the world, which are sold as cute pets once their mothers are slaughtered. Organizations, like the Tigapuluh Sumatran Orangutan Reintroduction Project, seek to rescue captured infants and rehabilitate them for reintroduction into the wild.
While endangered, Bornean orangutans are also surprisingly diverse, genetically speaking. Evidence shows that genetic diversity increases the likelihood that a population can bounce back from the brink of extinction. The reason lies in the power of an orangutan’s DNA, which offers more variety than a human’s. Orangutans have twice as many different nucleotide “letters” of their genetic codes as humans, meaning that they create more genetic variation naturally. Given their small population size of only 7,000, it is surprising that they would be more genetically diverse than Sumatran orangutans, but studies show that this is the case. Genetically diverse populations respond to environmental stressors better than populations with less variability. A wealth of genetic diversity means that a population is likely to have genes that can, and will, adapt to a novel environmental situation, like a change of food source or a new disease.
In all, Bornean orangutans are remarkably genetically diverse and are threatened by logging and poaching. Government agencies must form strong alliances with logging industries to raise awareness for the species before it is too late. Luckily, the genetic diversity of the Bornean population suggests that if measures are taken to protect them soon, they could bounce back and stave off further population decline.