When a dolphin whistles, what does it mean?

In this episode of Science Friday, host Flora Lichtman explores the mysterious world of dolphin communication, focusing on the meaning behind their signature whistles. Dr. Layla Saig, a senior research specialist at Woods Hole Oceanographic Institution, shares her groundbreaking work studying a long-term pod of bottlenose dolphins in Sarasota, Florida. She explains that signature whistles function like names in human society—unique to each individual and used for identification, especially when dolphins are out of visual range. These whistles are learned, often mimicking a mother’s call, though not always. The episode reveals fascinating insights into dolphin vocal behavior, including how mothers modify their whistles when communicating with calves, using higher-pitched, sing-song tones similar to human 'motherese.' Beyond signature whistles, Dr. Saig discusses non-signature whistles—previously dismissed as random—that appear to be shared among individuals and may serve specific communicative functions. The conversation also touches on the challenges of recording dolphin sounds underwater and the ethical and safety concerns of human interaction with wild dolphins, countering the romanticized image popularized by media like Flipper. The episode closes with a call to listeners to share their personal 'happy places' in honor of Earth Day.