ARI SHAPIRO, HOST:
For nearly a decade, scientists have been eavesdropping on killer whales in the Arctic.
(SOUNDBITE OF KILLER WHALES CALLING)
BRYNN KIMBER: So the whistles that you're hearing, the kind of primary noise - those are the killer whales. I've always kind of thought that they sounded like a distressed cat.
MARY LOUISE KELLY, HOST:
Brynn Kimber is with NOAA's National Marine Mammal Lab. Kimber points out that the Arctic is covered by ice and darkness much of the year, so underwater recordings come in handy.
KIMBER: When we have acoustics, we can actually track where these animals are in these more difficult-to-study areas.
SHAPIRO: Kimber's team has now gathered more than 140,000 hours of these recordings, and they've combed through that audio to identify the calls of killer whales.
(SOUNDBITE OF KILLER WHALES CALLING)
KELLY: That tape helps them map where the whales are and when, and they have found that killer whales are spending more time than they used to in the Arctic as sea ice dwindles due to climate change.
KIMBER: We have a recorder up at the Chukchi borderlands, which is very, very far north. We really didn't expect to see killer whales there at all. And when we looked at the recordings from this area, we still detected killer whales.
KELLY: Kimber presented the results this week in Seattle at a meeting of the Acoustical Society of America.
SHAPIRO: This could be good news for killer whales in the short term. Less sea ice means more real estate and more places to hunt.
KIMBER: If these tasty prey items that the killer whales would have loved to go for suddenly don't have any way to hide, you know, I can't see how that would be bad for killer whales.
SHAPIRO: But the inverse could be true for their prey, like endangered bowhead whales.
KIMBER: Often for bowheads, they've had kind of a sanctuary in the sea ice. Some of my colleagues have found that there is increasing scarring on bowhead whales from killer whale attacks.
KELLY: Sea ice is a sanctuary for many Arctic animals. Kimber says if the ice disappears, a lot of species will face dire conditions, and even the short-term advantage for the killer whales isn't likely to last.
(SOUNDBITE OF KILLER WHALES CALLING) Transcript provided by NPR, Copyright NPR.
