Friday, August 19, 2016

Happy World Orangutan Day- A Brief Review of Recent Research and News

Happy World Orangutan Day. Orangutans, both Bornean (Pongo pygmaeus) and Sumatran (Pongo abelli), are some of my favorite primates. These orange, solitary creatures live a primary arboreal life in the country of Indonesia on the islands of Borneo and Sumatra. They are highly intelligent and one of our closest living relatives. In honor of International Orangutan Day, I thought I'd celebrate with a post on some of the latest orangutan research.

Starting off with some good news: there are more Sumatran orangutans than was previously thought. There are possibly 8,000 more, bringing the total up to approximately 14, 600 individuals. Better methods and techniques are the main reasons behind the increase in numbers with areas previously not surveyed visited and orangutans found at elevations higher than researchers previously thought it was likely they inhabited.

Sumatran orangutans have been classified as critically endangered since they were first listed on the IUCN Redlist. However, Bornean orangutans were previously listed as endangered, until it was announced earlier this year that they have slipped to critically endangered as well. Habitat loss due to palm oil and rubber plantations threaten this species as well as hunting.

Rocky, an orangutan at the Indianapolis Zoo, can reproduce grunting sounds made by humans. He is able to mimic the pitch and tone of sounds made by humans and started mimicking at age eight. When compared to a database filled with the sounds of other orangutans, Rocky is unique. This new finding raises more questions about the development and origin of language in humans and what our last common ancestor with orangutans looked (and sounded?) like.

Another zoo-based study has shown that orangutans have the ability to use past experiences to create new images in their mind about new experiences. This ability is referred to as affective forecasting. Naong, an orangutan housed at a Swedish zoo, is able to guess whether he likes a new juice flavor based on the past juices he's tasted.  Originally given four flavors of juice, once Naong was familiar with these flavors, the juices were mixed together. Naong, if he observed the mixing, was able to guess whether or not he liked the mixed flavors based on his past preferences. This is yet another way humans are not as unique and different from our primate ancestors than perhaps we thought. Although anyone who has spent a significant amount of time observing these animals at a zoo or reading up on them probably won't be too surprised.

An unsettling study shows how just aggressive female orangutans can be. For the first time, researchers have observed the death of a female orangutan due to the aggressive actions of other orangutans. A young, female, Bornean orangutan attacked an older female with the help of a male orangutan for over thirty minutes. The two attackers traded off, with one attacking and the other preventing the victim from escaping. The older female later died as a result of her injuries. While aggressive behavior on this scale is known in chimpanzees, this is the first time such extreme behavior has been observed in wild female orangutans.

To end on a lighter note, a Sumatran orangutan has released his first music single. Playing on the drums and piano while a zookeeper recorded, Kluet is on his way to international fame perhaps. You can purchase the single here. Proceeds are going towards conservation efforts.

To conserve these animals and show your support for them, consider buying sustainable palm oil, being mindful of your overall consumption and energy expenditure, and donating your time or funds to charities that support these magnificent apes, such as Orangutan Foundation International, Bornean Orangutan Survival Foundation, or the Center for Great Apes.