Blue Whales Have A Very Efficient Feeding Style

An article from New Scientist states that Blue Whales are one of the more efficient eaters on the planet.  A team from the University of California tracked 250+ blue whales as part of a study to determine how the whales can support their high energy demand.  The massive amount of calories needed by the whales is due to their large size and  migratory lifestyle, along with having to live with the sparse prey populations for a significant portion of the year.

The Blue whale feeds on huge swarms of krill in the water column, netting more than 100 times the energy than researched expected them to. The whales dive up to 500 meters deep to find the large concentrations of krill. Diving below the krill, they lung upwards with mouths wide open, catching many many krill in the process. The whale then filters out the water through baleen, trapping the krill in the whales mouth.

The exact kilojoules of energy spent vs kilojoules of energy gained is in the link below.

http://www.newscientist.com/article/dn19841-blue-whale-feeding-methods-are-ultraefficient.html