Fig. 1.

This study combined field data, laboratory playbacks, and modeling. Points i–v are time aligned. (A) Suction cup video and 3D accelerometry tags were deployed on anchovy feeding (AF) humpback whales in California, USA. (B) Video recorded the behavior of schools as well as the timing of engulfment in relation to fish schools and to the whale’s own acceleration profile. Fish did not break the school until the mouth opening (MO) event. (C) Mean speed profile of a Type 1 humpback whale. Lunge feeding is most efficient when engulfment coincides with deceleration. (D) Speed and engulfment were parameterized into looming stimuli and played back to anchovies in the laboratory. Anchovies demonstrated C-start escape responses at consistent thresholds of dα/dt. (E) Stimuli parameterized from predator data, as opposed to a constant approach speed, increased rapidly after the tips of the jaws were wider than the whale’s maximum girth.