Minke Whales - Feeding

Minke whales are known to feed on a variety of prey species and their choice very much depends on what is available in the area. Feeding on different species requires different behaviours to entrap their prey, so around the world minke whales show a range of feeding behaviours.

The most commonly seen behaviour is lunge feeding – in which the whale lunges at the prey – often at high speeds with its mouth open and throat grooves extended. The mouth is then closed expelling the engulfed water through the baleen plates and then the trapped prey is swallowed.

These displays can be quite spectacular - sometimes the whale lunges vertically up from beneath the surface snapping its jaws shut in mid-air.

Off the west coast of Scotland minke whales lunge feed on small shoaling fish such as herring, sprat and possibly sand eel. Lunge feeding is often associated with the presence of seabirds and observations reveal a dynamic interaction between several bird species and the minke whales.

Using underwater cameras, researchers at Sea Life Surveys observed auks such as guillemots and razorbills diving down and picking off a small amount of fish from a larger shoal. The auks then dart backwards and forwards at the fish at high speed as they pick off individual fish. The frightened fish panic and bunch together in a tight ball and are driven to the surface waters, some leaping above the water.

Other seabird species such as kittiwakes and herring gulls see this commotion and swoop down to take the fish that they cannot normally reach. These squawking flocks of birds increase in size as more and more fly in to take the fish.

This commotion doesn’t go unnoticed and the minke whale takes advantage of this concentrated ball of fish and lunges up underneath the birds for an easy mouthful. Frequently, there are several flocks of birds gathered in the area at once and we have often sat watching whales for hours move from one flock to another gorging themselves on the plentiful fish. We call this "bird-associated" feeding.

Off the west coast of Scotland minke whales can also be seen lunge feeding without associating seabirds. These lunges seem to have more power to them, which may be a result of having to herd the fish such as sand eel. The whale actively concentrates the prey against the air/water interface and then lunges through the fish with its mouth open.

Birds are not associating at this time, although groups of Manx shearwaters are sometimes seen to hover over these foraging minke whales. On rare occasions we have observed whales swimming very slowly at the surface with their mouth slightly agape. We assume these to be skim feeding on plankton, which has gathered in the surface waters.