Blue whales are our planet’s largest animal; and for good reason. Scientists believe that they have cleverly adapted their feeding habits. Recent feeding studies have come closer to better explaining the massive whale size mystery. Why is it that, despite feeding on such tiny creatures (krill), blue whales are still so big?
Researchers claim that blue whales are even larger in size than the world’s largest dinosaur, called the Argentinosaurus. Surely they would need massive amounts of shrimp to satisfy their hunger. In fact, daily, blue whales consume over 4 tons of krill. The question, though, is how much energy they expend in tracking, cornering and securing their prey. After all, blue whales swallow massive amounts of water together with the shrimp-like creatures.
The latest study that has examined the feeding habits of blue whales attempted to better understand how blue whales support their enormous body size and whether they feed efficiently.
Blue whales encounter several issues when searching for food. You may be fooled into believing that their size alone is enough to ensure the animal’s next meal, but in reality, size has its burdens. For one, blue whales have no option of being stealthy when hunting. They also need to find enormous food quantities and they need to do so while not expending large amounts of energy.
Researchers from Oregon State University, Stanford University as well as NOAA experts reveal that blue whales have adapted their feeding behavior so as to make the best of what is available.
These massive animals are by no means indiscriminate eaters (as we were previously led to believe). IN fact, blue whales use sophisticated foraging strategies in order to target dense krill populations. After having followed the feeding behavior of 14 blue whales, researchers compared their results to those of 41 previously tagged blue whales. They used acoustic surveys to measure the density of the krill populations they chose to feed on.
The researchers concluded that blue whales fed more frequently when krill populations were denser. As soon as krill population densities increased, blue whales started employing “lunge-feeding” strategies, so as to maximize the krill quantities they consumed per dive.
According to Ari Friedlaender, study investigator, such behavior proves that blue whales make educated decisions in order to increase the amounts of krill they ingest. While this type of “lunge-feeding” is demanding in terms of energy, “the increase in the amount of energy they get from increased krill consumption more than makes up for it,” Stanford University marine biologist Jeremy Goldbogen explains.
Photo credits: KrillFacts