Humpback Comeback

Whale watchers worldwide got a bit of good news this week, with the release of a new study that says humpback whales are making a comeback in the North Pacific.

According to the study, the number of whales in the North Pacific may have reached 20,000 for the period between 2004 and 2006. That's up from a total of fewer than 1,500 whales 40 years ago, when humpback hunting was banned.

Experts still worry that some humpback subgroups are taking longer to bounce back, but one described the news as "definitely very encouraging in terms of the recovery of the species." It's certainly enough to make us want to dive in for a closer look at one of the ocean's marvelous mammals.

Uproarious Rorquals

Humpbacks hail from the family of whales called "rorquals," which includes the fin whale, the sei whale, and the blue whale, the world's largest animal. Blue whales can grow to 100 feet (30 meters) and weigh up to 330,000 pounds (150 metric tons), bigger than any dinosaur we've yet discovered.

At 45 feet (14 meters) and 80,000 pounds (36 metric tons), humpbacks aren't nearly as big as cousin Blue. But they can really sing. In fact, according to a 2006 study, humpback whales sing grammatically, combining sounds into phrases, and phrases into songs, according to complex rules called a "hierarchical syntax." It's similar to our ability to combine words into clauses and clauses into sentences.

Humpbacks can dance, too. They are among the most acrobatic of whales, sometimes leaping entirely out of the water. Such breaching is common among males during mating season, when humpbacks migrate from polar feeding grounds to tropical breeding grounds. It's also during mating season that humpback males sing their syntactically sophisticated songs, presumably in pursuit of humpback gals.

Straining for Snacks

Like all rorquals, humpbacks are baleen whales. They feed by taking huge mouthfuls of seawater--literally tons of it--then forcing the water out between hundreds of plates of baleen (a.k.a. "whalebone") that hang from the roofs of their mouths. The baleen plates work like a sieve, letting water out but keeping krill and other munchable marine life in.

To catch that seafood dinner, humpbacks sometimes use a special technique called "bubblenetting." First, one or more humpbacks swim in a circle beneath a school of fish, blowing bubbles that float up to form a wall around their prey. Then the humpbacks swim up through their "bubblenet," slurping the fish-filled water as they go.

It's clever, and tremendously effective. A humpback whale can catch, and eat, as much as 3,000 pounds (1,360 kg) of food in a day. But that's not too surprising--coming from a creature smart enough to sing in syntax.