The three orangutans at Pairi Daiza zoo, Belgium, developed a “special bond” with the otters after their river was run through the ape enclosure on March 2020. The zoo said it enriched both species’ environments. An animal – and this is even more the case of orangutans, with whom humans share 97 per cent of their DNA – must be entertained, occupied, challenged and kept busy mentally, emotionally and physically at all times. (Photo by Pascale Jones/The Sun)

Khansa, an eight month old critically endangered Bornean orangutan shows off it's two front-teeth, at the Singapore Zoo on Thursday, January 11, 2018 in Singapore. The Singapore Zoo is active with its breeding programs as part of its wildlife preservation efforts. This is the Zoo's 46th successful orangutan birth. (Photo by Wong Maye-E/AP Photo)

A baby orangutan called Barney shows off his dancing at Ragunan Zoo in Jakarta, Indonesia in the first decade of November 2023. (Photo by Syahrul Ramadan/Media Drum Images)

Bornean orangutan (Pongo pygmaeus). Tanjung Puting National Park, Borneo – winner of the gold and grand prizes in the 2020 world nature photography awards. (Photo by Thomas Vijayan/World Nature Photography Awards)

1st Place in Wildlife: A male orangutan peers from behind a tree while crossing a river in Borneo, Indonesia. (Photo by Jayaprakash Joghee Bojan/National Geographic Nature Photographer of the Year contest 2017)

This picture taken on December 15, 2019 shows three young orangutans after they were rescued by police from illegal wildlife traffickers in Pekanbaru in Riau province, Indonesia. (Photo by Wahyudi/Jefta Images/Barcroft Media)

Three-year-old orangutan from Sumatra, Berani, is pictured at the Pairi Daiza wildlife park, zoo and botanical garden in Brugelette, Belgium on August 2, 2019. (Photo by Yves Herman/Reuters)

Meet the star students of orangutan school – the unique rehab centre where orphaned apes are taught how to climb trees and survive in the wild without their mum and dad. (Photo by Caters News)