Primate communication is more than just monkeying around

Monkeys may have more to say for themselves than has been thought. Scientists have found that the primates have developed a language with similar speech patterns to humans.

A study in the west African country of Ivory Coast by a team from the University of St Andrews, found that monkeys have developed a much larger vocabulary than had been realised and that they use the same kind of vocal inflection as humans to distinguish between words. Dr Klaus Zuberbuhler, from St Andrews' School of Psychology, who carried out the experiments in the rainforests of the Tai National Park also found that monkeys use specific "words" for different situations.

Dr Zuberbuhler monitored the responses of Campbell's monkey and the Diana monkey, both of which are under threat of extinction from poaching and deforestation, to recordings of their own warning cries.

In potentially dangerous situations the male Campbell's monkey produced a "boom" noise before issuing a distinct alarm call. Similar results were found with the Diana monkeys.

While specific predators, such as leopards or crowned-hawk eagles, were identified by a unique warning sound, the use of the "boom" noise appears to be used only when the monkeys sense danger but are unsure of the attacker.

"The use of the "boom" could be compared to man's use of the word 'maybe'," Dr Zuberbuhler said. "[The sound] modified the meaning of the alarm calls and transformed them from highly specific warnings, requiring immediate anti-predator responses, into more general signals of disturbance.

"Although the analogies to human language remain suggestive, the results show that monkeys can ... implement the same sentence structure rules that humans use."