Blue whales are moaning and purring off the New York coast.

The endangered mammals have been positively identified for the first time in New York coastal waters by acoustics experts at the Cornell Lab of Ornithology's Bioacoustics Research Program.

Christopher Clark, director of the program, said blue whales are the largest animals ever to have lived on Earth and their voices can travel across an ocean. One was recorded about 70 miles offshore from Long Island and New York City in January and a second one was recorded farther in the distance.

When speeded up 10 to 20 times, recordings of the whales' vocalizations sound like low moans and purrs. At normal speed, they're too low for humans to hear.

The research will help guide whale protection efforts.