How Much Krill Can a Blue Whale Swallow?

Unlike toothed whales that hunt for individual prey, baleen whales -- including the blue whale, the largest animal on Earth -- eat an enormous quantity of food in one big gulp. When a blue whale opens its mouth 80 degrees, it can hoover up large schools of tiny crustaceans called krill, consuming as much as 1,100 lbs. (500 kg) at a time. And for a blue whale, a single mouthful of food can contain 457,000 calories, making each foray a relatively efficient and satisfying meal.

A whale of an appetite:

• Instead of teeth, filter-feeding whales use baleen, which are plates with frayed edges in the upper jaw that filter out tiny seafood from the water.
• Baleen whales' feeding efficiency is unprecedented, says researcher Robert Shadwick. “When they take a gulp of water, they are filling their mouths with the amount of water equal to their own body mass.”
• Plates of baleen are made of keratin, a protein found in hair, fingernails, and feathers.

Frequently Asked Questions

How much krill does a blue whale consume in a day?

A blue whale can consume up to 4 tons of krill per day. This massive intake is necessary to sustain its equally massive body size, which can reach lengths of up to 100 feet and weights of approximately 200 tons. The whale's diet is almost exclusively krill, small shrimp-like creatures abundant in cold ocean waters.

What is the feeding mechanism of a blue whale for swallowing krill?

Blue whales use a technique called lunge feeding to swallow large quantities of krill. They accelerate towards a swarm of krill with their mouths open, engulfing water and prey. Their pleated throat grooves expand, allowing them to take in a huge volume. Then, they filter out the water and retain the krill using baleen plates.

How does the amount of krill a blue whale eats affect the ecosystem?

Blue whales play a crucial role in marine ecosystems by affecting krill populations. Their consumption helps regulate the abundance of krill, which in turn influences the Antarctic food web. According to ecologists, this predation can lead to healthier krill populations by preventing overpopulation and ensuring a balanced ecosystem.

Can blue whales survive on food other than krill?

While krill is the primary diet of blue whales, they can occasionally consume small fish and other zooplankton if krill is scarce. However, these are not as nutritionally dense or as easily available in large quantities as krill, making krill the optimal food source for sustaining their enormous energy requirements.

How do blue whales find enough krill to eat?

Blue whales locate krill by following their seasonal migrations and aggregations. They often feed in areas with high concentrations of krill, such as cold, nutrient-rich waters where krill breed and feed. The whales' migration patterns are closely tied to these krill hotspots, ensuring a consistent food supply.

What impact does climate change have on blue whale feeding habits?

Climate change poses a significant threat to blue whale feeding habits by altering ocean temperatures and currents, which can affect krill populations and distribution. Warmer ocean temperatures may shift krill habitats, making it more challenging for blue whales to find sufficient food. This could lead to changes in migration patterns and reduced reproductive success for the whales.