Globescan:
Orangutans smarter than previously thought
Their nest building is highly sophisticated, say experts Scientists
at the University of Manchester spent a year observing and filming
orangutans at a research facility in Indonesia and found they apparently
possess complex knowledge of mechanical design and material properties.
The great apes -- which only live wild in Sumatra and Borneo and are one
of man's closest relatives -- build large, oval nests in tree canopies
every day where they sleep overnight, possibly for protection from
predators and parasites or for warmth during sleep.

Until now, little was known about the nests’ mechanical design and
material properties but the researchers, led by Dr Roland Ennos, and
carried out by PhD student Adam van Casteren, reported that the
orangutans used particular branches for different parts of the nest.
They also broke the branches in different ways depending on how they
would be used.“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 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 right off to make a sort mattress. They seem
to have learnt about the mechanical properties of wood, and 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.
-ScienceDaily |