Most whales feed mainly on the smallest organisms in the food chain : krill, zooplankton and small fish, which they ingest in enormous quantities, with some variations depending on the species. For example, fin whales make up their diet of krill, copepods, squid, and small fish, while humpback, Bryde, and dwarf whales make up for krill and minnows. They employ different tactics to collect and ingest food, ranging from the tracking of the right whale, which swims slowly with its mouth wide open through swarms of zooplankton, to the more direct of the fin whale, which quenches its hunger by swallowing huge mouthfuls. of living beings and water.
However, humpback whales ( Megaptera novaeangliae ) resort to a more sophisticated strategy that requires teamwork . They feed mainly in the summer and live off their fat stores during the winter. They eat infrequently and opportunistically during their sojourn in warm and temperate waters while wintering at the poles. They feed on krill and schools of small fish such as herring, salmon, capelin, mackerel and chickadee in the North Atlantic. In Australian and Antarctic waters, they eat krill and copepods.
To hunt, what they do is dive in groups of at least four or five individuals and stir the waters through their nostrils to create nets of bubbles in which large amounts of krill are trapped . The ring of bubbles surrounds the school of fish and gradually closes until the catch is confined in a smaller and smaller cylinder. They then rise to the surface while devouring the succulent morsel of their catch. The slotted plates in the mouth allow them to easily drain all the water taken in the maneuver. The ring formed by the bubbles can measure up to 30 meters in diameter and requires the cooperation of several animals .
The humpback whale is one of the largest fin whales, adults measuring 12 to 16 m in length and weighing 36 tons. The species has a distinctive body shape, with long pectoral fins and a gnarled head. It is an acrobatic animal that frequently jumps on the surface and then hits the water. Males emit a complex song, which lasts ten to twenty minutes and repeats for hours at a time. The purpose of the song is unclear, although it appears to play a role in mating.
