Alva Review-Courier -

WASHINGTON (AP) — 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.

A study published Monday found that female bottlenose dolphins change their tone when addressing their calves. Researchers recorded the signature whistles of 19 mother dolphins in Florida, when accompanied by their young offspring and when swimming alone or with other adults.

The dolphin signature whistle is a unique and important signal — akin to calling out their own name.

"They use these whistles to keep track of each...