Zookeepers at Central Park Zoo have discovered whispered communication amongst the cotton-top tamarin, a species of monkey in the zoo. Researchers had intended to record alarm calls used between the primates when threatened by the presence of humans, but found they reverted to silence in those situations. A further analysis of the recording gives evidence of whispered communication between the animals when faced with potential threats. This is the first time whispering between non-human primates has ever been recorded. Communication between cotton-top tamarins has also displayed eveidence of a sophisticated grammatical structure. Researchers Rachel Morrison and Diana Reiss published their findings in the journal Zoo Biology, and speculated that the whispering could be evidence of convergent evolution in communication strategies used by social and cooperative species.
Read the original article and hear a sound clip of the recorded whisperings here.