Not only did the data show that these humpbacks, "by far the most acrobatic of all baleen whales," Ware says, were performing bottom side-rolls and seafloor scooping, it indicates that this bottom feeding does not include lunging, previously assumed to be the humpbacks' primary feeding behavior.
In lunge feeding, whales accelerates to propel water full of prey into their enlarged mouths; they then filter the water out through the hair-like filaments of their baleens and retain the prey. Tag data showed that the bottom-feeding humpbacks were moving at too low a speed to characterize this behavior as lunge feeding.
While a Crittercam a National Geographic Society video camera that gives a whale's-eye view -- attached to a humpback provides additional insight into the whales' time at the seafloor, Ware cautions that there's plenty to learn about what the whales are doing in the deep.
"The big mystery is we still don't know exactly how they're feeding. We don't know the mechanism," he says.
|Contact: Beth Potier|
University of New Hampshire