Researchers studying a group of six tufted blond capuchins in the northeastern Brazil Atlantic Forest were in for a surprise when they discovered the monkeys using a novel technique to fish for termites. The technique, reported in the latest Royal Society Biology Letters, has never been documented before for primates, including humans.
“Our observations started when the capuchins were already fishing for termites,” said lead author Antonio Souto, a researcher in the Department of Zoology at the Federal University of Pernambuco. “Under these circumstances, we can only speculate how this behaviour began.”
Under a grant from the National Council for Scientific and Technological Development the researchers were studying the group when they found that the three male of the group used a very different method to fish for termites. It involved many steps and was used to extract termites located in high forest canopies usually 30 feet above the ground.
“It is tempting to believe that a serendipitous discovery was made by one of the members of the group and then other capuchins learned how to do it through observation.” said Souto.
The technique began with the monkey using its tail to wrap around a tree branch and sit in a squatting position on a limb. The monkey then tapped the sides of the termite nest followed by breaking a branch of the tree to use as a spoon to fish the termites out. The individual then used a rotating motion to insert the stick into the nest, removed it, inspected the attached termites and then ate them.
Souto explained how the technique was advanced and successful in fishing more termites.
“When a nest is disturbed by an object breaking into its walls, soldiers (of this Brazilian termite species) swarm at the place where the break occurs,” Souto explained. “Our results indicate that tapping the walls before inserting a stick increases the number of extracted termites, possibly because soldiers enter into a state of alert prior to the break, enhancing their response toward the strange object.”
They also found out that by rotating the stick the capuchins ensured that it did not break. The motion also helped in causing more aberrations in the nest and created a hole.
The research shows that tool innovation is still happening in the primate world and opens new ideas as to how innovation takes place.
Apart from termites capuchins eat fruits, spiders, small vertebrates, an occasional sweet sip of sugar cane, and insects. The researchers believe it is their varied diet that helped with the tool innovation.
The capuchins are a critically endangered species of monkey and there are only 180 left in the world.
Other primate experts found the research interesting and relevant. Sauto hopes that these rare monkeys are protected and genetic analysis be carried out. He hopes the forest corridors where the monkeys roam are protected and conservation efforts are stronger.