BEIJING, March 8 (Xinhuanet) -- Blue whalelove songs are no longer a secret from the prying ears of researchers at the Scripps Institution of Oceanography in San Diego, Calif.

Scientists used tags suctioned to the whales' bodies and tracked the whales. They discovered that as they feed, they broadcast calls to let each other know where they are, each groupusing a different sound, media reported Thursday.

The noises also play an important role during mating season when males sing long, low-pitched songs to indicate their reproductive fitness to females. Females select mates based on size and make a decisionby evaluating males' songs. They know larger males can take in more air and hold notes longer.

Theresearchers say the dialect findings could help guide conservation efforts for blue whales, whose numbers dwindled to dangerously low levels before whalinglaws were enacted. Scripps scientast John Hildebrand told LiveSciencethere were once an estimated 200,000 to 300,000 in the Southern Hemisphere, but today that number is closer to 1,000.

"By listening to the animals," he explained, "you can tell something about the areas in which they are interacting to breed and that's important to know for managing and conserving the animals."

The research appears in the Jan. 25 issue of the Marine Ecology Progress Series journal.

A related study, also by Scripps researchers, foundthere are distinct "dialects" of whale-speak in different regions of the ocean. The finding could have implications for preservation efforts.

The scientists used acoustic recordings to delineate nine population regions worldwide. They found the whales weren't evenly distributed.Populations using a "Type 1" call, for example, live within a narrow band of ocean hugging the North American coast, while whales that use a "Type 4" call are spread over a large swath of the Northern Pacific Ocean.

The second study was published in a recent issue of the Journal of Cetacean Research Management.

(Agencies)