summary
Rorqual baleen whales lunge feed by engulfment of tons of
prey-laden water in a large and expandable buccal pouch. According to prior
interpretations, feeding rorquals are brought to a near-halt at the end of each
lunge by drag forces primarily generated by the open mouth. Accelerating the body
from a standstill is energetically costly and is purported to be the key factor
determining oxygen consumption in lunge-feeding rorquals, explaining the
shorter dive times than expected given their sizes. Here, we use multi-sensor
archival tags (DTAGs) sampling at high rates in a fine-scale kinematic study of
lunge feeding to examine the sequence of events within lunges and how energy
may be expended and conserved in the process of prey capture. Analysis of 479
lunges from five humpback whales reveals that the whales accelerate as they
acquire prey, opening their gape in synchrony with strong fluke strokes.
journal reference (summary free): Experimental Biology >>