Baleen Whales
Birds and Mammals that Depend on the Salish Sea: A Compilation
The biomechanics of lunge-feeding whales: marine science lecture recap
At the Marine Science Lecture at Camp Orkila on Jan 18, 2011, Dr. Jeremy Goldbogen of the Cascadia Research Collective spoke about current research into "lunge-feeding" whales.
Goldbogen studies biomechanics in rorqual whales, the group that includes blue, fin and humpback whales.
Rorqual whales are distinguished by their "ventral groove blubber" which allows their mouth to expand to a huge volume when feeding.
The whales feed by lunging at concentrations of food -- in most cases masses of krill, but also herring and other small fish -- and engulfing great amounts of water and prey. Like other baleen whales, they then expel the water and retain the food.
(Other baleen whales feed differently. Some filter continuously, swimming with their mouths open so that food gets trapped in baleen plates.)
Goldbogen has used specialized sensors to collect data as whales dive as deep as 250 meters. One of the mysteries of these whales has been why the don't stay underwater as long as other whales of similar size.
Goldbogen's research shows that the whales use an enormous amount of energy on each dive. In the fin whales he studied, the whales dove underneath big patches of krill and attacked them from underneath (which prevents the krill from seeing the whale coming). They are going very fast until they open their mouths, at which point the open mouth acts like a parachute and slows the whale down abruptly.
Want to read more?
Read Jeremy Goldbogen's 2006 paper, "Kinematics of foraging dives and lunge-feeding in fin whales." (It includes graphs showing dive profiles, as well as images of the bioacoustic probes and discussion of how the probes were attached.)
For a more general-interest view, take a look at this three part series by Darren Naish at scienceblogs.com. It's got photos of jaws, and a couple pics of Jeremy Goldbogen.
