Monkeys Can Whisper

Hello here is the deck. You're old and you don't care.

      A cotton-top tamarin. Photo by  via  

As far as the cotton-top tamarins at are concerned, there is one zoo supervisor that is enemy number one.  He was a part of the team that captured them in the wild and he is always around to supervise the tiny primates鈥 medical procedures.  As soon as he comes around, the monkeys start whispering to each other 鈥 a new discovery that has scientists talking as well. 

City University of New York researchers, Rachel Morrison and Diana Reiss, were to study primate communication when they noticed the whispering behavior.  They had been trying to elicit an 鈥渁larm call鈥 (a loud screatch to notify the arrival of a predator) by having the zoo supervisor walk into the tamarin鈥檚 enclosure. They had picked this particular supervisor because of his history with the tamarins.  In the past, they had even 鈥渕obbed鈥 him, making ear-splitting noises and lunging at him. The researchers expected the creatures to do the same again, and had video and audio recorders set up to capture it. Instead, what they witnessed was that the primates appeared to go silent. 

Upon later analysis of the recordings, the researchers amplified the sound and discovered that the one-pound creatures were in fact making very soft chirps, too low for the humans to hear. The scientists deduced that these whispery chirps, called 鈥渓ow amplitude signaling,鈥 were a more cautious type of alarm.

There are a handful of . A female fish, called the , will whisper purrs to its mate to initiate sex and one species of bat, , uses whispering as a technique to avoid detection by moths with ears, so that they can eat them.  But up until now, no one has caught a monkey or an ape in the act, making the tamarins the first non-human primates to whisper. They are also the first animals to use whispering for the same reason that we do: to avoid being overheard by an unwelcome guest or predator.  

Morrison and Reiss, who published their results in , acknowledge that it is impossible to know for sure what the monkeys are saying to each other. However, by observing their behavior, they surmised that the tamarins were warning each other about the threat while trying to avoid detection. They also suspect that other species may also whisper for the same reason, but so far, no one has heard them.