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Different Behaviours Worldwide

A number of studies suggest that the Common minke whales apply different feeding strategies and techniques in response to predominant environmental factors (upwellings, fronts, tidal currents, topography) and the density and type of prey available. In some areas they might also be related to the presence of other predators (e.g. piscivorous fish species, seabirds).

While minke whales in Scotland may apply bird associated feeding such interspecies interaction is extremely rare in the St. Lawrence. In fact, if such interaction occurs, it is the birds that follow the hunting whale to profit from the prey being pushed to the surface by the whale itself. Instead, these minke whales show a large variety of “active” entrapment and engulfing behaviours.

The hunter’s speed is prey related

Minkes in the St. Lawrence might feed on euphausiids (Thysanoessa raschi and Meganyctiphanes norvegica) when super abundant and in sufficient densities, applying rather slow and low angle-feeding strikes. Their major prey, however, consists of capelin (Mallotus villosus), which is reported to be the most predominant shoaling fish species in the Saguenay and neighbouring areas of the St. Lawrence. Here upwellings, currents and the unique underwater topography often entrap krill and fish near or right at the surface.

Thus, the St. Lawrence whales are ideal to observe and record the surface geometry, breathing intervals, various speeds and orientations, different body planes and manoeuvres, and continuous body movements of a hunting minke whale. Our long-term studies show that they are highly plastic in applying, developing and adjusting manoeuvres over time. To which extend these various manoeuvres are applied at depth however, is not yet known.

Turning into different body planes

Today we distinguish two types of behaviours, the entrapment and engulfing manoeuvres, which can be applied either in

1. dorsal-ventral
2. ventral-dorsal
3. lateral plane
4. vertical plane