To record dolphin sounds, we place non-invasive hydrophones mounted on suction cups on a dolphin’s melon (“forehead”) and record the sounds that they make.
We’ve been recording dolphin whistles since the 1970s. Today, the Sarasota Dolphin Whistle Database contains 926 recording sessions of 293 individual dolphins; we know the age, sex and the matrilineage for most of them.
One of the things these recordings have allowed our acoustics colleagues from Woods Hole Oceanographic Institution (WHOI) and the University of St. Andrews to do is find support for the 1960s hypothesis by David and Melba Caldwell that each individual dolphin has a unique signature whistle. These whistles allow them to recognize others of their species as individuals with separate identities — almost as if they were names.
A new paper published in the peer-reviewed journal Frontiers in Marine Science — “The Sarasota Dolphin Whistle Database: A unique long-term resource for understanding dolphin communication” — outlines how we’ve studied the differences among individual dolphin whistles, what these differences mean and the many ways our colleagues are using this database to help unlock the mysteries of how and why dolphins communicate.
Studies have focused on classifying whistles, the context of whistle production, whistle development and stability, whistle copying, non-signature whistles, and playback studies of whistle function and perception.
The paper’s lead author is Dr. Laela Sayigh, research specialist at WHOI. Laela has been studying the whistles of Sarasota’s dolphins since the mid-1980s, when this was the topic of her WHOI/MIT doctoral dissertation. She also presented information about the database during the 24th Biennial Conference on the Biology of Marine Mammals in August 2022.
- Read the paper here
- The cover of our last annual report, Nicks ‘n’ Notches, showed a visual representation of the signature whistles of all 269 Sarasota Bay dolphins who have been recorded. The image was prepared by our colleague Frants Jensen. Check it out here.
- Watch the video below to listen to the differences in dolphin whistles. You can also visit our “Meet the Dolphins” section to listen to more Sarasota Bay dolphin voices.