Author: University of Miami
Publication date: October 21, 2014
URL: http://www.sciencedaily.com/releases/2014/10/141021125943.htm
Summary:
Thaddeus McRae, an assistant research biology professor for the University of Miami, is researching the way squirrels communicate with each other. After thoroughly observing and studying squirrel colonies on the campus at Coral Gables, Florida, he noticed patterns in the sounds, expressions, and gestures that squirrels make. He wondered if these sounds and motions were used as a means of communication, particularly for alerting other squirrels of predatory threats. To observe the squirrels' reactions to ground and air predators, McRae constructed a remote controlled cat, painted gliders to look like eagles, and sent them to chase the squirrels around the university campus. While doing this, he recorded and observed specifically three common sounds, a short bark, a squeal, and a whistle, as well as two common tail "twitches", a movement in an arc shape and a movement in wavy patterns. After two years of research, McRae could accurately predict the predator in the squirrels' vicinity simply by watching the combination of sound and tail movement of a squirrel.
Relevance:
McRae's experiment determined that the squirrels' sounds and communicative actions are adaptations as a result of predator-prey relationships. The squirrels have evolved over time to develop a system of avoiding predators, much like the snakes in the case study from class developed mimicry. Additionally, McRae used both discovery and hypothesis-based science to come up with and validate his idea of predator alerts between squirrels. His observations of common squirrels around the university campus revealed a pattern in their gestures and noises, and this led him to form the hypothesis that the communication was a means of community survival. From this, he developed a test to gather more data, and using the data, he was able to make predictions. Thus, McRae clearly followed the steps of the scientific method throughout the course of his research.
Was there a specific "predator signal" that he found for humans or were they just for the specific predators?
ReplyDeleteThe way I understand it is that he found signals for categories of predators, such as land or air, large or small, etc. Squirrels may possibly have signals for other, non-predatory species like humans, but I doubt that McRae has identified those.
DeleteWhen the squirrels were frightened and showed these signals would other squirrels repeat it or just run away?
ReplyDeleteMcRae predicted that the signals were for warning other squirrels that it has been spotted. The other squirrels would likely not repeat the signal, because that may reveal their location to the predator and there would be no need to signal seeing as they have not been spotted yet.
DeleteTo clarify, the squirrels would probably just run away.
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