Navigation Links
Blue whale-sized mouthfuls make foraging super efficient
Date:12/9/2010

Diving blue whales can dive for anything up to 15 minutes. However, Bob Shadwick from the University of British Columbia, Canada, explains that blue whales may be able to dive for longer, because of the colossal oxygen supplies they could carry in their blood and muscles, so why don't they? 'The theory was that what they are doing under water must use a lot of energy,' says Shadwick. Explaining that the whales feed by lunging repeatedly through deep shoals of krill, engulfing their own body weight in water before filtering out the nutritious crustaceans, Shadwick says, 'It was thought that the huge drag effect when they feed and reaccelerate this gigantic body must be the cost'. However, measuring the energetics of blue whale lunges at depth seemed almost impossible until Shadwick and his student Jeremy Goldbogen got chatting to John Hildebrand, John Calambokidis, Erin Oleson and Greg Schorr who were skilfully attaching hydrophones, pressure sensors and two-axis accelerometers to the elusive animals. Shadwick and Goldbogen realised that they could use Calambokidis's measurements to calculate the energetic cost of blue whale lunges. They publish their discovery that blue whales swallow almost 2,000,000kJ (almost 480,000kcalories) in a mouthful of krill, and take in 90 times as much energy as they burn during a single dive in The Journal of Experimental Biology at http://jeb.biologists.org.

Analysing the behaviour of each whale, Goldbogen saw that dives lasted between 3.1 and 15.2 minutes and a whale could lunge as many as 6 times during a single dive. Having found previously that he could correlate the acoustic noise of the water swishing past the hydrophone with the speed at which a whale was moving, Goldbogen calculated the blue whales' speeds as they lunged repeatedly during each dive. Next the team had to calculate the forces exerted on the whales as they accelerated their colossal mouthful of water. Noticing that the whales' mouths inflated almost like a parachute as they engulfed the krill, Goldbogen tracked down parachute aerodynamics expert Jean Potvin to help them build a mathematical model to calculate the forces acting on the whales as they lunged. With Potvin on the team, they were able to calculate that the whales used between 3226 kJ of energy during each lunge. But how did this compare with the amount of energy that the whales could extract from each gigantic mouthful of krill?

Goldbogen estimated the volume of the whales' mouths by searching the whaling literature for morphological data and teamed up with paleontologist Nick Pyenson to measure the size of blue whale jaw bones in several natural history museums. He also obtained krill density values from the literature which are probably on the low side. Then he calculated the volume of water and amount of krill that a whale could engulf and found that the whales could consume anything from 34,776kJ up to an unprecedented 1,912,680kJ from a single mouthful of krill, providing as much as 240 times as much energy as the animals used in a single lunge. And when the team calculated the amount of energy that a whale could take on board during a dive, they found that each foraging dive could provide 90 times as much energy as they used.

Shadwick admits that he was initially surprised that the whales' foraging dives were so efficient. 'We went over the numbers a lot,' he remembers, but then he and Goldbogen realised that the whales' immense efficiency makes sense. 'The key to this is the size factor because they can engulf such a large volume with so much food in it that it really pays off,' says Shadwick.


'/>"/>

Contact: Kathryn Knight
kathryn@biologists.com
44-078-763-44333
The Company of Biologists
Source:Eurekalert

Related biology news :

1. Human cells exhibit foraging behavior like amoebae and bacteria
2. Dining out in an ocean of plastic: How foraging albatrosses put plastic on the menu
3. Bumblebees learn the sweet smell of foraging success
4. Argonne scientists awarded supercomputing time to enable scientific breakthroughs
5. Super-sized world: Conference addresses global obesity epidemic, explores policies, interventions
6. New standard proposed for supercomputing
7. Study shows young, unsupervised children most at risk for dog bites
8. Supercomputer makes it possible to develop a Brazilian Global Climate System Model
9. NOAA, Wisconsin officials designate 17,000-acre research reserve on Lake Superior
10. Behind-the-scenes advances underpin new super-strong plastics
11. San Diego Supercomputer Center participates in first Census of Marine Life
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2017)... TEANECK, N.J. , May 16, 2017  Veratad ... leading provider of online age and identity verification solutions, ... the K(NO)W Identity Conference 2017, May 15 thru May ... Ronald Regan Building and International Trade Center. ... across the globe and in today,s quickly evolving digital ...
(Date:4/18/2017)... -- Socionext Inc., a global expert in SoC-based imaging and computing solutions, ... which features the company,s hybrid codec technology. A demonstration utilizing TeraFaces ... will be showcased during the upcoming Medtec Japan at Tokyo Big ... Las Vegas Convention Center April 24-27. ... Click here for an image of ...
(Date:4/11/2017)... DUBLIN , Apr. 11, 2017 Research ... Tracking Market 2017-2021" report to their offering. ... The global eye tracking market to grow at ... The report, Global Eye Tracking Market 2017-2021, has been prepared based ... report covers the market landscape and its growth prospects over the ...
Breaking Biology News(10 mins):
(Date:6/23/2017)... and CARDIFF, UK (PRWEB) , ... June 23, 2017 , ... ... and Brian Lula, president of Physik Instrumente USA, have been selected as this year’s ... photonics . , The two have been invited along with other honorees to accept ...
(Date:6/23/2017)... ... 23, 2017 , ... The Academy of Model Aeronautics (AMA), ... Association (UAA), the unifying voice for collegiate aviation education, are launching a joint ... and success through a STEM-based education platform. , Much like the program currently ...
(Date:6/22/2017)... ... June 21, 2017 , ... RMC Pharmaceutical ... and engages Timothy Reinhardt to manage the new site. , Tim has 25 ... with his most recent role as the Director of Manufacturing and Supplier Quality ...
(Date:6/22/2017)... Wendelsheim, Germany (PRWEB) , ... June 22, 2017 ... ... , is taking over the allergy specialists DST Diagnostische Systeme & Technologien GmbH, ... We all know someone who suffers from hay fever, urticaria, asthma, atopic eczema ...
Breaking Biology Technology: