Dolly and Donna, two dolphins at the Nuremberg Zoo in Germany, appear to be able to sense electric fields — an ability that might help them detect prey buried in sand or enhance their navigation.

Transcript

ARI SHAPIRO, HOST:

All right, everybody, say hello to Dolly and Donna.

(SOUNDBITE OF DOLPHINS VOCALIZING)

SHAPIRO: If you couldn't tell, Dolly and Donna are bottlenose dolphins, and they live at the Nuremberg Zoo in Germany, where scientists recently taught the dolphins a game to investigate their sensory abilities.

TIM HUTTNER: We know a lot of their visual abilities, their hearing abilities, their abilities in terms of echolocation. But what we were investigating with two bottlenose dolphins were their ability to sense electric fields in the water.

AILSA CHANG, HOST:

Their ability to sense electric fields in the water, or electroreception. Biologist Tim Huttner says it's a common trick among some types of ocean life. Sharks and rays use it to detect the weak electric fields emanating from the bodies of their prey.

SHAPIRO: In a new study described in the Journal of Experimental Biology, Huttner and his team trained Dolly and Donna to swim away from a small underwater apparatus when they detected a weak electric field. When they got it right, they got a reward of fish or squid.

CHANG: The scientists found that the dolphins are not as sensitive as sharks, but Huttner says they're still sensitive enough to use this ability in the same way - to detect prey, especially when hunting on a murky seabed.

HUTTNER: Right before the dolphin snaps at the fish and tries to catch it, and especially when it's stuck headfirst in the sand, echolocation and vision become limited, and then electroreception could guide the dolphin to successfully snap the fish.

KYLE NEWTON: The great thing about this paper is it's a behavioral evidence that, yes, these animals can actually detect a particular stimulus and use it in their natural behaviors.

SHAPIRO: Kyle Newton is with Oregon State University's Hatfield Marine Science Center. He was not involved in the research, but says this ability could also help dolphins map where they are in the world by sensing the electric charge their bodies produce as they swim through the Earth's magnetic field.

NEWTON: Animals can theoretically use that induced charge around them as an indicator of where they might be on the surface of the Earth relative to maybe where they want to go.

CHANG: Newton also says it's a reminder that not all animals experience the world as we do.

NEWTON: And it's really cool. How can that not be really inspiring and just makes you wonder, like, wow, what else are we missing?

CHANG: Yeah. I mean, what else are scientists missing? But, Ari, I personally feel like I am missing a vital sense here. Like, I want to have electroreception.

SHAPIRO: Just keep swimming, Ailsa, just keep swimming. Transcript provided by NPR, Copyright NPR.