Seeking the loneliest whale

An enigmatic whale roams the North Pacific, and next year Bruce Mate will lead a monthlong expedition to find it. Mate, director of Oregon State University’s Marine Mammal Institute in Newport, is no revenge-obsessed Captain Ahab. And the object of the quest is no ferocious leviathan: It is probably one of the generally meek baleen whales that prey on creatures close to the base of the food chain.

No one has ever seen this particular whale (“that they know of,” says Mate), but researchers know it’s out there. Its distinctive 52-hertz calls — similar to those of blue whales and fin whales but higher in pitch — have been recorded since 1989 by various researchers and the U.S. Navy.

Scientists have some notions about the mystery whale: It’s probably a male, says Mate, since its calls pierce the seas only during mating season. The whale has been tracked swimming as far as 11,000 kilometers in a single season, so it’s apparently healthy. Because the whale’s path doesn’t seem to line up with those of other species inhabiting the same region, the cetacean has been dubbed by some “the loneliest whale in the world.”

Mate doesn’t buy that moniker for a number of reasons. For one thing, he says, females typically don’t respond vocally to a male’s mating calls; they simply show up, so scientists would not have heard them. He also doesn’t think it’s the last member of an unknown species hunted to near extinction. Instead, it’s more likely to be a hybrid between two known species, or possibly an individual with a malformation in its sound-producing organs — the cetacean equivalent of a lisp. “It wouldn’t surprise me to find a large number of other whales in his vicinity when we find him.”

In fact, Mate is counting on it. Although the expedition will be funded by a team of documentary filmmakers searching specifically for the falsetto whale, Mate hopes to tag about a dozen other whales. That will give him a rare chance to learn what whales do between feeding season, when they gorge themselves to build up fat stores, and breeding season.

“We’re trying to track these whales from the season we know to the season that we don’t,” he says. “There hasn’t been an experiment yet where we didn’t have “an ‘a-ha’ moment. — Sid Perkins

Whale hide-and-seek

Marine biologist Bruce Mate and his colleagues have pioneered techniques for tagging whales with hockey puck–sized instrument packages to track migratory and feeding habits. Here are a few examples of what they’re learning from tagging data about whale behavior and populations.

Eddy feeding
Baleen whales sometimes seek out and follow large, kilometers-wide ocean eddies and feed within them or along their edges, taking advantage of biological hot spots that are created as eddies bring cold, nutrient-rich waters to the surface.

Tag-team hunting
Sperm whales, which normally forage alone for prey such as giant squid, occasionally hunt in tag teams. One whale dives deep to prevent prey from escaping downward while its companions herd the animals into dense schools and then lunge into the feast.

Oil spill–related detours
Mate and his colleagues are now collecting data that could reveal whether the massive 2010 Deepwater Horizon oil spill has substantially affected sperm whales’ migratory and feeding patterns in the northern Gulf of Mexico.