I want to know more

Three St. Lawrence rorqual whales, three different strategies

Blue whales feed almost exclusively on krill. They ingest 2 to 4 tonnes per day. Krill can be found low in the water column during the day, possibly to avoid predators. At night, they rise to the surface to feed on algae and copepods. Not surprisingly night is a time when blue whales are often seen surface feeding. The sight of a blue whale swimming along the surface on its side, its enormous mouth dislocated, is a breathtaking spectacle. After having witnessed this behaviour, it becomes easier to understand how many fabulous legends of sea monsters came about. Have no fear; they pose no threat to humans. The oesophagus of the blue whale is about the size of a large orange. It would be impossible for this giant to swallow us!

Another species worth observing in feeding mode is the minke whale. They can often be found in rip tides taking advantage of fish that get trapped between cold and warmer water masses. They chase their prey upward, trapping them at the surface. They then shoot half out of the water, or emerge sideways allowing observers a glimpse of under belly, pectoral fin, half of a tailÉ It is not always easy for a novice to understand what exactly it was that so suddenly broke the surface!

As for fin whales, these large, slim and rapid rorqual whales often feed in synchronized groups. They surface in closed formation in groups ranging anywhere from twelve to more than twenty at a time. It is then possible to watch them turn in a semi-circular fashion, a little bit like an enchanted carousel where, one after another, they dive for a few seconds then surface again for another breath of air. The merry-go-round ends a few minutes later as, one behind the other, each whale arches its back before diving and disappearing. Does this technique allow fin whales to co-operate to catch fish more efficiently? Or is this a form of competition aimed at obtaining the lion's share of the meal?