Mechanics, Hydrodynamics and Energetics of Blue Whale Lunge Feeding: Efficiency Dependence on Krill Density

• Main Authors: Goldbogen, J. A., Calambokidis, J., Oleson, E., Potvin, J., Pyenson, N. D., Schorr, G., Shadwick, R. E.
• Other Authors: BRITISH COLUMBIA UNIV VANCOUVER DEPT OF ZOOLOGY
• Format: Text
• Language: English
• Published: 2011
• Subjects: Biological Oceanography; Fluid Mechanics; *WHALES; *HYDRODYNAMICS; *FEEDING; *DRAG; MODELS; LIPIDS; GRAPHS; ENERGY; EFFICIENCY; DEPTH; WEIGHT; TABLES(DATA); MARINE BIOLOGY; EQUATIONS; THRUST; DIVING; BUOYANCY; HIGH COSTS; DENSITY; CRUSTACEA; KINEMATICS; REPRINTS; *PREY DENSITY; LUNGE FEEDING; RORQUAL WHALES; KRILL; BLUE WHALES; ENGULFMENT CAPACITY; AMR(ACTIVE METABOLIC RATE); BMR(BASAL METABOLIC RATE); BALEEN WHALES; FILTER FEEDING; FORAGING; ENERGETICS; LIPID DEPOSITION; VGB(VENTRAL GROOVE BLUBBER); ENERGY EXPENDITURE; TMJ(TEMPOROMANDIBULAR JOINT); TADL(THEORETICAL AEROBIC DIVE LIMIT); BLFM(BASIC LUNGE FEEDING MODEL); Rorqual; Balaenoptera musculus; baleen whales; Blue whale
• Online Access: http://www.dtic.mil/docs/citations/ADA538663; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA538663

Lunge feeding by rorqual whales (Balaenopteridae) is associated with a high energetic cost that decreases diving capacity, thereby limiting access to dense prey patches at depth. Despite this cost, rorquals exhibit high rates of lipid deposition and extremely large maximum body size. To address this paradox, we integrated kinematic data from digital tags with unsteady hydrodynamic models to estimate the energy budget for lunges and foraging dives of blue whales (Balaenoptera musculus), the largest rorqual and living mammal. Our analysis suggests that, despite the large amount of mechanical work required to lunge feed, a large amount of prey and, therefore, energy is obtained during engulfment. Furthermore, we suggest that foraging efficiency for blue whales is significantly higher than for other marine mammals by nearly an order of magnitude, but only if lunges target extremely high densities of krill. The high predicted efficiency is attributed to the enhanced engulfment capacity, rapid filter rate and low mass-specific metabolic rate associated with large body size in blue whales. These results highlight the importance of high prey density, regardless of prey patch depth, for efficient bulk filter feeding in baleen whales and may explain some diel changes in foraging behavior in rorqual whales. Published in the Journal of Experimental Biology, v214 p131-146, 2011. Sponsored in part by SERDP, CNO/N45, and NSERC.