In this undated photo, bottlenose dolphins swim in open waters off Sarasota Bay, Florida. Photo taken under NMFS MMPA Permit No. 20455 issued to the Sarasota Dolphin Research Program. A new study has found that female bottlenose dolphins change how they vocalize when addressing their calves. WASHINGTON — — You know instantly when someone is speaking to an infant or small child. It turns out that dolphin mothers also use a kind of high-pitched baby talk.
“They use these whistles to keep track of each other. They’re periodically saying, ‘I’m here, I’m here’,” said study co-author Laela Sayigh, a Woods Hole Oceanographic Institution marine biologist in Massachusetts. Obtaining this data was no simple feat. Over more than three decades, scientists placed special microphones multiple times on the same wild dolphin mothers in Florida's Sarasota Bay to record their signature whistles. That included years when they had calves and when they didn't — dolphin calves stay with their mothers for an average of three years in Sarasota, and sometimes longer. Fathers don't play a prolonged role in parenting.