Blue whales became the biggest animal to live due to their feeding strategy and efficiency to catch Krill and small fish. Due to their special hunting and eating skills, they become the biggest animal. Ballen whales have bristle instead of teeth in their mouths. This bristle acts as a filter. Blue and humpback whales belong to the Ballen category. Bristle is keratin structure which helps whale to gulp huge amount of water along with krill, small fish and plankton. This way allows them to consume more calories.
Dolphin and Orcas have tooth and they have to hunt for larger prey to survive. The amount of krill present in the ocean during the summer months will define the growth of animals. Lage consumption of food helps them to grow in size. Compared with smaller whales, larger whales have wider mouths, which allows them to consume more amount of water at a time along with the prey. According to the researchers, the size depends upon the quantity of prey available. Jeremy Goldbogen, Stanford University biologist, said that it is in the month of summers where Ballen whales can gain more energy from Krill. They have a highly efficient feeding strategy that allows them to store fat. These fat can later be converted into energy during migrations or breeding at lower levels of oceans where there is less food.
The research was carried out on 300 whales, dolphins and porpoises of various sizes. They attached temporary tags to whales, which transmitted the data to the research team on the boat. The tags tracked the moment of the whales. The density of prey near each animal was estimated by sonar devices and prey in the whale’s stomach. Results showed that only the whales having filters were able to maximize their feeding strategy and grow in size. For toothed whales, it became difficult to grow in size. Toothed whales use echolocation to catch a single prey underneath the water, which is very difficult to catch.