Orangutans on Borneo are observed using tools to catch fish
Posted May 10 2011 12:00am
Mother and baby orangutan at a refuge on Borneo. Photo: Sally Kneidel
Field researcher Anne Russon of York University in Toronto monitored orangutan behavior from 2004 to 2007 on the Indonesian island of Borneo. She observed orangutans scavenging fish that had washed up along shores. She also saw them grabbing live catfish out of small ponds. The orangutans immediately ate the fish.
In 2007, Russon stocked a small pond with catfish and videotaped orangutan visits to this pond. She reported that several of the red apes learned on their own to jab at catfish with sticks, provoking the fish to flop out of the ponds within reach. The orangutans then ate them.
Using sticks to frighten fish out of ponds qualifies as "tool use," an ability that was once thought to be unique to humans. Other primates and crows have also been observed using tools to obtain food, and sometimes making tools. Chimps have been filmed making spears to stab and remove small primates from treeholes and then eat them. (The spears are made by sharpening sticks with their teeth.) Chimps also use sticks to remove termites from holes to eat.
If any of you readers can tell me other observations of meat-eating or tool-use in orangutans, I'd like to know.
Russon reported her observations of orangutans catching fish at the 'American Association of Physical Anthropologists' meeting in Minneapolis on April 14, 2011.