“An Analysis of Rachel Morrison and Diana Reiss’s Whisper-like Behavior in a Non-human Primate”
Imagine you are at home with a loved one. The two of you are reading in your bedroom, and all of a sudden you hear an intruder smashing a window downstairs. Fear immediately sets in, and you begin to mentally cycle through your options. You whisper to your loved one to quietly move and hide in the closet while you dial 911. You proceed to whisper to the 911 dispatcher about the incident that has just taken place as you are notified a patrol unit is just three minutes away. The intruder is not attempting to be discreet, and you can tell exactly where the person is in the house. Your location has not been disclosed because opposed to panicking and running down the stairs, you remained calm and began to whisper. Whispering may have well saved your life.
This year Morrison and Reiss published the first signs of whisper-like vocalizations in non-human primates. The group to which this was discovered was a family of cotton-top tamarins; the mating pair, and three of their offspring. The family of tamarins are captive-born and kept at the Central Park Zoo in New York City. Morrison and Reiss were intending to study the tamarin’s antipredator calls and mobbing behavior towards humans they view as predators based off the conclusions presented by Campbell and Snowdon in 2007. Morrison and Reiss wanted to see if the findings would remain consistent. While they expected to find the tamarins growl, bark, and/or jump down onto the employee responsible for capturing animals with a net, they found the exact opposite. When the employee was within their presence, the tamarins reduced their calls substantially and remained using their normal whistles and chirps.
Whisper-like Behavior in a Non-human Primate has not been cited by any other articles at this moment. Morrison and Reiss did take the time to cite a few other articles focused on the whisper-like calls of other animals such as the gray warbler and mouse-eared bats. The most prominent citations seemed to come from Campbell and Snowdon’s Vocal Response of Captive-reared Saguinus Oedipus During Mobbing. This was the article that prompted Morrison and Reiss to perform the research they did. It was already known that tamarins produce various antipredator calls and mobbing behavior, but Campbell and Snowdon were first to discover tarmins producing different antipredator calls towards humans such as growls, barks, and high-chirp trills.
Morrison and Reiss did use scientific method in their 2008 study. They asked if the tamarin’s responses would be comparable to those viewed by Campbell and Snowdon. They hypothesized that the tamarins would react similarly due to the aforementioned research. They developed an experiment using a zoo employee that had been singled out to have already illicit mobbing-like responses from the tamarins. They then modified their experiment after it not working the first time. After altering their experiment, they then performed it three more times. Their results did not align with their hypothesis, and due to background noise they would have to later analyze audio recordings. Audio recordings were analyzed using software specifically designed for applications such as theirs. After drawing conclusions they then communicated their results through the Zoo Biology publication.
Research was presented well and in a concise manner. I will be the first to admit that zoo biology is not my expertise, but I was able to understand the findings presented by Morrison and Reiss. They did go in depth regarding their recording techniques,, but I was able to easily follow along due having a background in audio recording. I was not drawn to execute additional research for further clarification on the topic presented.
The first day the experiment was executed the employee was placed outside the viewing area of the tamarin’s holding enclosure. Due to no change behavior, Morrison and Reiss had to alter the experiment. The altered experiment was performed only three more times throughout the same month. Baseline data was gathered on other days between the experiment days. Morrison and Reiss had also gathered recordings of the tamarins pre and post exposure to the employee which would be critical for comparison to the recordings of tamarins being exposed to the employee.
I was disappointed that the experiment was performed only four times, and really three times if you disclude the failed first attempt. It was also a disappointment that the researchers were limited so heavily by the employees schedule. The pre and post-employee recordings were 15 minutes, but only three to five minutes of recording was gathered during employee exposure. Maybe these are superficial complaints, but if I were performing this research I would think a duration equal to or longer than the pre and post recordings would be important. Who is to say the tamarins would not have began lashing out at the employee after maybe seven minutes? While the researchers were capable of getting roughly consistent results technically only two times (background noise degraded a post recording on day two), can they really draw conclusions?
Other experiments will have to be executed in order to draw further data, and thankfully Morrison and Reiss came to that same conclusion, “We acknowledge that more data are necessary to make conclusive statements about the function of whisper-like behavior in cotton-top tamarins and we hope that our findings encourage the search for this phenomenon in other groups of cotton-top tamarins and other highly cooperative primate and non-primate species.” [Morrison and Reiss, 2013]
At the beginning of this paper I presented a horrible hypothetical situation in which a human whispers to preserve the life of a loved one and his/herself. I opened up with this because that hypothetical situation was what first came to mind after reading, Whisper-like Behavior in a Non-human Primate. I’ve really only viewed whispering as a means to avoid a third-party hearing something I simply do not want them to hear. It only makes sense that if other primates “whisper,” we may have simply missed it due to not listening for that method of communication. If their whispers have gone unnoticed by humans, then that lack of hearing only reinforces their success rate. More evidence is needed, but it seems that other primates are wanting their communications to remain unnoticed much like humans are constantly wanting.
In conclusion we all want some privacy, and depending on the situation we will react either cautiously or in a mobbing manner to a threat. Why should we be surprised if our furry brethren do the same?
