By Eve Wackett

When watching a group of animals, how does one tell who is the leader? If one fish decides to go left instead of straight, why do the others decide to follow that one fish? Do whirligig beetles know where they are going when they seem to scurry around like chickens with their heads cut off?

The Great Lakes Center for Environmental Research and Education invited William L. Romey, assistant biology professor from SUNY Potsdam, to speak about his research on animal grouping dynamics.

Romey showed theories related to whirligig beetles and schools of fish and how individual actions in the group impact the group as a whole. He said there are many advantages and disadvantages for animals living in a group. Some of the advantages he mentioned were:

• mating – more choices to pick from for the perfect mate
• thermoregulation – groups can keep each other warm or cool
• feeding – hunger or lack of it determines the placement in the group (front/back)
• predator avoidance – more eyes and ears to look out for predators

To illustrate predator avoidance, Romey juggled yellow balls. He started with one ball to show how easy it is for a predator to zero in on an individual. Romey then added two balls to illustrate how a predator may be confused by the added motion of the targets. He threw in an orange ball to show how a predator would be more or less attracted to the individual that stood out in the group.

How an individual places himself within a group is based on several factors:

• physiology — hunger, toxins, hormones
• behavior – choose, NND (nearest neighbor distance), position
• population – group size, group trajectory (turning/speed), group shape

Romey showed a video to illustrate how he collected and marked beetles, or schools of fish, and made use of computers to analyze their positions. The example looked like a video game. In fact, Romey has been complimented on his neat screensavers that were actual studies he had been working on. The students in his classes are able to have some fun with the research because Romey created a video game based on the movements of the group; students just click on the beetle they think is the leader of the group.





For the answers, click here.