New study investigates the environmental cues dolphins use to migrate on the Atlantic coast of North America

Date: April 22, 2016

Source: De Gruyter

Seasonal migration patterns of bottlenose dolphins -- what we know for sure? With the changing of the seasons comes the urge to migrate for many animals of the world, whether they be furred, feathered, or even finned. One finned animal in particular, the common bottlenose dolphin, undertakes seasonal migrations each spring and fall, but how the dolphins know when to migrate has not always been clear. It was usually assumed that their southern migration begins when the ocean waters drop in temperature. However, until now there was little evidence to support this and it was largely unknown what factors influence the initiation of dolphin migration. A new study has discovered some of the factors that influence these seasonal migrations.

In the article, published this week and available online, Masters student Anna Taylor, from the University of Georgia (USA), and colleagues studied the common bottlenose dolphin, which migrates seasonally along the southeastern United States Atlantic coast. While this species of dolphin is widely studied, surprisingly little is known about what influences the timing of these migrations.

The scientists needed to track the comings and goings of dolphins at their study sites on the Georgia and South Carolina coasts, and they did so using photographic identification of individual dolphin fins. This technique is used with many studies of Cetaceans (whales, dolphins and porpoises), which all have dorsal fins. As the animals age, their dorsal (back) fins become worn and chipped, which allows individuals to be uniquely identified, much like fingerprints.

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