How Do Monkeys Communicate?

If it is just after sunset in the South American rain forest, you might hear Howler Monkeys bellowing. Usually one monkey starts off and others join in as if they were singing in a choir. Scientists think that the male Howlers use vocal competitions to attract the females. If a Tamarin monkey finds himself all alone, he whistles so that his group will wait for him or else call back so he can catch up. Baboons post guards who cry warnings when enemies come. Other monkeys have warning cries, too. Interestingly, females don't respond to warning cries given by strange males–they just seem to hear the warnings from their own male friends. Of course, baby monkeys of all kinds cry out when they need something from their mothers.

Scientists have spent years trying to understand monkey communication. They have learned that individual calls may not mean much of anything, but when certain calls are made in a certain order, they can be interpreted. The same sounds that tell monkeys to beware of a leopard in the grass can be rearranged to say that a hungry eagle is nearby. Scientists also believe that when monkeys know each other, they seem to be able to recognize each other's voices.

Diana monkeys live in the same area as hornbill birds in the Ivory Coast of Africa. They sometimes feed and rest in the same treesm and they both fear being eaten by crowned eagles. When either the hornbills or the monkeys signal that there is a crowned eagle, both types of animals understand and hide.