Click the full-screen arrows in the upper right to read the captions!

Here's a conversation worth talking about: A mother dolphin chats with her baby…over the telephone! The special call was made in an aquarium in Hawaii, where the mother and her two-year-old calf swam in separate tanks connected by a special underwater audio link. The two dolphins began squawking and chirping to each other—distinctive dolphin chatter.

Cracking the Code

"It seemed clear that they knew who they were talking with," says Don White, whose Project Delphis ran the experiment. "Information was passing back and forth pretty quickly." But what were they saying? That's what scientists are trying to find out by studying wild and captive dolphins all over the world to decipher their secret language. They haven't completely cracked the code yet, but they're listening … and learning.

Chatty Mammals

In many ways, you are just like the more than 30 species of dolphins that swim in the world's oceans and rivers. Dolphins are mammals, like you are, and must swim to the surface to breathe air. Just as you might, they team up in pods, or groups, to accomplish tasks. And they're smart.

They also talk to each other. Starting from birth, dolphins squawk, whistle, click, and squeak. "Sometimes one dolphin will vocalize and then another will seem to answer," says Sara Waller, who studies bottlenose dolphins off the California coast. "And sometimes members of a pod vocalize in different patterns at the same time, much like many people chattering at a party." And just as you gesture and change facial expressions as you talk, dolphins communicate nonverbally through body postures, jaw claps, bubble blowing, and fin caresses.

Thinking Dolphin

Scientists think dolphins "talk" about everything from basic facts like their age to their emotional state. "I speculate that they say things like 'there are some good fish over here,' or 'watch out for that shark because he's hunting,'" says Denise Herzing, who studies dolphins in the Bahamas.

When the going gets tough, for instance, some dolphins call for backup. After being bullied by a duo of bottlenose dolphins, one spotted dolphin returned to the scene the next day with a few pals to chase and harass one of the bully bottlenose dolphins. "It's as if the spotted dolphin communicated to his buddies that he needed their help, then led them in search of this guy," says Herzing, who watched the scuffle.

Language Lessons

Kathleen Dudzinski, director of the Dolphin Communication Project, has listened to dolphins for more than 17 years, using high-tech gear to record and analyze every nuance of their language. But she says she's far from speaking "dolphin" yet. Part of the reason is the elusiveness of the animals. Dolphins are fast swimmers who can stay underwater for up to ten minutes between breaths. "It's like studying an iceberg because they spend most of their lives underwater," Dudzinski says.

Deciphering "dolphin speak" is also tricky because their language is so dependent on what they're doing, whether they're playing, fighting, or going after tasty fish. It's no different for humans. Think about when you raise a hand to say hello. Under other circumstances, the same gesture can mean good-bye, stop, or that something costs five bucks. It's the same for dolphins. During fights, for example, dolphins clap their jaws to say "back off!" But they jaw clap while playing, too, as if to show who's king of the underwater playground.

"I have not found one particular dolphin behavior that means the same thing every time you see it," says Dudzinski. "If you like mysteries and detective work, then this is the job for you." And who knows—maybe someday you'll get a phone call from a dolphin.