New feeding organ discovered that might detect prey densities

Scientists have discovered an organ in the jaw of rorqual whales, like blue whales, that might detect sufficient prey densities to then initiate feeding lunges, which are energetically expensive and only worth it if enough food is taken in to compensate for the energetic costs. Read about it at:
http://www.sciencedaily.com/releases/2012/05/120523133242.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fplants_animals%2Fdolphins_and_whales+%28ScienceDaily%3A+Plants+%26+Animals+News+--+Dolphins+and+Whales%29