At the Pairi Daiza zoo in Belgium, a family of three Borneo orangutans has forged an unusual friendship with their fieldmates, a group of Asian small-clawed otters. Keepers made the decision to put these two species in a shared enclosure with hopes that they would keep each other entertained and, judging by the photographs, they were not wrong.
Orangutan means “man of the forest” in Malay, which is precisely where these exceptionally intelligent primates live in the wild, with populations in Borneo and Sumatra. They share 97 percent of their DNA with humans, which explains why they share many of the same needs as people when it comes to engagement and enrichment. They're so similar in fact, some have even been documented making human-like sounds with their own "faux language" which researchers have attempted to translate. To account for this, the Pairi Diaza zoo in Belgium has put together a rich and diverse "enrichment" program for their resident orangutans, of which they have five, which center around their keepers engaging the animals in mind games, puzzles, and physical challenges.
To bolster this enrichment, the decision was made to keep their family of three orangutans, Ujian, Sari and baby Berani, who arrived at the zoo in 2017 from the German zoo of Heidelberg, in isolation, in a shared enclosure with a group of otters. While these two animals don’t coexist in the wild today it’s possible that extant populations of orangutans found in Southeast Asia and South China could have overlapped with the species' habitat.
By putting the two different highly social species together they can each benefit from consistent interaction and play with their neighbors. The Pairi Daiza zoo facilitated this by housing their otters in the river that flows through the orangutan enclosure. In an email to IFLScience the zoo explained, “The otters really enjoy getting out of the water on the orangutan island to go and play with their big, furry friends. Especially baby Berani and daddy Ujian [who] have developed a very special bond with their neighbors. It makes life more fun and interesting for both animal species, which makes it a very successful experiment.”
The Borneo orangutans are one of three species of orangutan in the region and are extremely threatened in the wild due to devastating deforestation predominantly from harvesting palm oil. In the past 60 years the wild population has declined by 60 percent. The Pairi Daiza zoo is involved in a project to restore a part of the Borneo forest for the wild population, and thanks to Ujian, Berani, and Sari they have raised enough money to plant 11,000 new trees in Borneo. You can find out more about the project to tackle deforestation here.