Thursday, November 3, 2011

Blue whale's rare above-surface vocalization caught on video

From PetathomasonOutdoors: Blue whale's rare above-surface vocalization caught on video
A small portion of extremely rare above-surface blue whale vocalization has become available as part of NBC footage obtained on a trip Tuesday aboard the Christopher out of Long Beach. The peculiar sound can be heard at about the 1:00 mark on the accompanying video clip. The event also was witnessed by a marine biologist, a naturalist and the whale-watching vessel's owner and crew.

Also observed was what appeared to be courtship behavior, which also is rare off California, where the whales spend part of each summer and fall gorging on tiny shrimp-like krill. This involved four whales, one of them noticeably larger and perhaps a female.

The larger whale was the one that surfaced alongside the vessel and, with much of its head above the surface, issued a deep, low-pitch groan that lasted about eight seconds. This occurred a second time later during the 20-minute encounter. It remains unclear if this type of event has ever been documented.

Also unclear is why the film crew didn't capture more of the episode, but it had been seeking blue whale visuals, not vocalizations.

"We heard it through the air, loud and clear," said Alisa Schulman-Janiger, an American Cetacean Society biologist and researcher. "It was a strange, alien sound. It really was an extraordinary thing."

Kera Mathes, a naturalist with the Aquarium of the Pacific, described the experience as "astounding." The aquarium posted on its Facebook page Thursday that the bizarre sound was, in fact, captured on film.

Blue whales communicate, for up to hundreds of miles, with low-pitched vocalizations. The vocalizations can sometimes be picked up via submerged hydrophones. But the majestic leviathans, which are the planet's largest creatures and can measure 100 feet and weigh 150 tons, are not known for making sounds other than those associated with breathing while at the surface.

About 2,000 blue whales -- part of an endangered global population of roughly 10,000 -- migrate into California waters in early summer to take advantage of vast blooms of krill.

The whales feed almost constantly but the four whales alongside the Christopher were clearly cavorting. They lunged, or raced across the surface, at times lifting their heads and chin-slapping in what seemed a game of follow the leader. Typically during this type of behavior, the leader is a lone female.

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