While we humans may congratulate ourselves with LEED Certification and other honors every time we make an eco-friendly building, it seems that we are not the only species to have engineering skills that are capable of green design. According to a new report from the University of Manchester, the orangutan – man’s closest genetic relative – has evolved engineering knowledge that allows it to build nests in the Indonesian treetops.
Photo © Chi King
The project, led by Dr. Roland Ennos and carried out by PhD student Adam van Casteren, is the result of a year-long study into how orangutans carefully selected twigs, branches and leaves in order to construct nests each night – with skills matching those of engineering students. Until now, little was known about the nests’ mechanical design and material properties but the researchers found that the orangutans used particular branches for different parts of the nest and broke them in different ways depending on their usage.
“We found that the orangutans chose strong, rigid tree branches for the structural parts of the nests that supported their weight, and weaker, more flexible branches for the nest’s linings, suggesting that the apes’ choice of branch for different parts of the nests was dictated by the branches’ diameter and rigidity,” said Dr Ennos, based in the University of Manchester’s Faculty of Life Sciences.
“Further, branches chosen for the nests’ structural framework were fractured differently from those chosen for the lining: whereas structural branches were broken halfway across, leaving them attached, branches used for lining were completely severed, suggesting that orangutans might use knowledge of the different ways in which branches break to build strong and comfortable nests.”
The authors, writing in the journal Proceedings of the National Academy of Sciences, suggest that orangutans, like some birds, might possess engineering expertise. Dr Ennos added: “We witnessed orangutans building safe, comfortable nests by half-breaking and weaving thick branches and twisting smaller branches together to make a sort mattress. They seem to have learned about the mechanical properties of wood, and they use this knowledge in a clever way.
“Our research has implications for the evolution of intelligence and cognition as well as the evolution of tool use in early humans. It provides evidence that the development of all these traits started in apes because of their need to understand their mechanical environment, not just their social environment.”