Whales in Calif. river seemingly tone deaf

, Calif., May 17 (UPI) -- Wildlife experts were frustrated Thursday when their attempts to use whale sounds to draw two whales out of a California river proved fruitless.

The San Jose Mercury News said that after emitting recorded whale sounds throughout the Sacramento River most of Thursday, the humpback whales that have resided there for nearly a week appeared undisturbed by the sudden soundtrack.

Experts, who had planned on using the sounds to draw the mammals to the safety of the ocean, said they were not giving up on the sound-based plan.

But one expert said the sounds may need to be adjusted its take into account for, of all things, where the whales originally came from.

Alaska Whale Foundation official Pieter Folkens said the whale sounds currently being used are from Alaskan whales and the two runaways may be used to another whale dialect.

"This is a humpback probably from a different population, probably the Mexico-California population," Folkens told the newspaper. "So it's kind of like speaking Chinese to somebody from Boston, but at least you recognize that it might be another member of the same species."