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:1/24/2017)... , Jan. 24, 2017 Biopharm Reports ... the laboratory use of nuclear magnetic resonance spectroscopy ... end-users and profiled current practices, developments, trends and ... well as growth and opportunities. These areas include ... NMR instruments, needs and innovation requirements, hyphenated NMR ...
(Date:1/23/2017)... Jan. 23, 2017  The latest mobile market research ... have dropped dramatically. The quarterly average price of a ... $276 in Q4 2016.  There are now 120 sub-$150 ... $116, up from just 28 a year ago at ... to Maxine Most , Acuity Market Intelligence Principal, ...
(Date:1/19/2017)... and PUNE, India , January 19, 2017 ... Biometric Sensor Market, Opportunities and Forecast, 2014 - 2022," the global biometric ... CAGR of 9.6% from 2016 to 2022. In 2015, Asia-Pacific ... security for both public and private sectors. Continue ... ...
Breaking Biology News(10 mins):
(Date:2/23/2017)... and NEW YORK , ... Lumeon , a leading digital health company, ... a provider of telemedicine and remote patient monitoring, ... for telemedicine reimbursements.  DN Telehealth ... patients, in real-time, extending consultations beyond a physical ...
(Date:2/23/2017)... ... February 23, 2017 , ... BellBrook Labs is ... include an array of biochemical analyses critical for Lead Discovery. The company’s ... and SAR programs, including inhibitor potency and selectivity, mechanism of action, and inhibitor ...
(Date:2/23/2017)... , Feb. 23, 2017  MIODx announced today ... two key immunotherapy technologies from the University of ... a method to monitor a patient for response ... and CTLA-4.  The second license extends the technology ... is likely to have an immune-related adverse event ...
(Date:2/23/2017)... -- Seattle,s upscale Capitol Hill neighborhood, with its swanky shops, parks and ... lice treatment salon to set up shop. But there,s ... French bistro on E Madison Ave, and CEO Maria ... lice clinic, we pride ourselves on being a destination for ... the stigma associated with lice. Everyone can get lice – ...
Breaking Biology Technology: