How Do Whales Eat: How, Why, When, Frequency, And Several Facts

Whales are large mammals with a unique diet pattern. Let us together learn how whales eat.

Whales, like blue whales, have baleen plates, which helps them take in large quantities of water and filter their food from it through the help of these plates. These baleen plates act as a sieve and help the whale derive their food. Other toothed whale varieties, such as beaked whales, have a set of teeth that helps them bite and chew on their prey.

There are a lot of doubts people have regarding the eating habits of whales, including the frequency and food type. Let us together answer some of these questions and delve into certain facts and figures.

Image Credits: “Antarctic blue whale” by Oregon State University is marked with CC BY-SA 2.0.

How do whales eat krill?

It is a common known fact that whales consume large quantities of krill, among other things. But, how do they eat krill? Let us find out. 

Whales eat krill through their baleen plates. Certain whales like humpbacks or blue whales are baleen animals and do not have teeth. As such, they take in large quantities of water in one gulp that is concentrated with krill, and their baleen plates help filter out or extract the krill from the water. Thus, whales can easily eat krill this way.

As you might already know, krill forms a major part of a whale’s diet. Although not all whales have baleen plates, those that do can easily feed on krill using this filtration method.

Image Credits: “humpback whale, morro rock and smokestacks” by minicooper93402 is marked with CC BY 2.0.

How do whales eat without swallowing water?

It is natural to assume whales swallow water while eating. But that’s not true. Let us tell you more in this regard. 

Whales have a “plug” that separates the channel that exists between their pharynx and mouth. They do this primarily by the use of their muscles which spring in action to protect the animal’s digestive and respiratory tract. However, whales do gulp large quantities of water while eating, but they are able to push back that water while only ingesting small quantities of it.

This imaginary plug is slightly similar to the ones that human beings have. Just like the human body can differentiate between respiratory and digestive tracts, the whale body can do so too.

How often do whales eat?

Naturally, large animals like whales will need to eat often to swim effortlessly and carry out all their activities. Let’s find out how often they eat.

You’d be surprised to know that most whale species, such as humpback whales and other baleen whales, only eat for 100 days in a year. This annual cycle is termed as the “feast or famine cycle,” and whales typically eat during the summer season, which is also when they breed. The rest of the year, they choose not to have any food.

Some whales can go without eating for a period of six months. This is because their body stores the food they need for the year during the feasting season.

How much do whales eat in a day?

Now that you know how often whales eat, allow us to tell you more about how much they eat in a day.

The food quantity that whales eats per day strictly depends on the species. For instance, blue whales may eat around 10 to 20 tonnes of food per day. On average, most whale species consume around 16 tonnes of food in a day. As a rough estimate, it is generally agreed upon that whales need to eat at least 30% of their body weight to sustain themselves. 

Whales generally consume a lot of food and derive their energy from the regular consumption of food like krill, fish, and other animals.

How many calories do whales eat?

Whales need to consume a set amount of calories per day to keep going. Allow us to tell you more in this regard.

Whales can consume around 20 to 50 million calories per day. Although this might sound surprising, remember that whales are huge animals that need more calories than humans do. For instance, a single gulp of food consumed by blue whales can contain up to 457,000 calories. In comparison, most human beings usually need 2,000-2500 calories per day.

Whales also need a lot of energy for movement and food procurement. Therefore, they need a higher than normal amount of calories to function to their full potential.

How do whales eat fish?

Curious to know how whales manage to eat fish? Let us tell you more in this regard. 

Whales eat fish and even squid either by directly grabbing and biting them or by slowly drawing them and swallowing them whole. Sometimes, the fish might be too big to be swallowed whole. In such cases, they grip the prey and tear them into small pieces. However, this is mostly the case for toothed whales.

On the other hand, baleen whales usually feed only on krill, and therefore their baleen plates spring into action and filter the food for them.

How many fish do whales eat in a day?

As you might already know, whales need large quantities of food per day. Allow us to tell you how many fishes they eat per day.

Whales can eat around 4,000 to 5,000 tonnes of fish and other animals per day, including krill and plankton. Humpback whales, in particular, can easily consume around four tonnes of fish in a day, and blue whales can consume slightly more than this. On average, most whale varieties consume 3.8 tonnes of fish or other small creatures in a day.

It is important to note here that fishes, squid, and other creatures form an imperative part of the whale’s diet. Therefore, regular consumption of these animals helps the whale maintain its efficiency.

How do whales eat without teeth?

Image Credits: “baleen whale!” by hanjeanwat is marked with CC BY 2.0.

Wondering how whales manage to eat their food without teeth? Let us find out together. 

Whales are of two varieties: toothed and baleen. The baleen whales do not have teeth but baleen plates which act as a sieve and help filter the food (mostly krill) through the water. Most whale varieties, including blue whales and humpback whales, are baleen whales, and therefore, they manage to eat without their teeth.

We must mention here that krill forms the major part of the baleen whale’s diet, and therefore, they do not need teeth to gulp down this food.

How do whales eat underwater?

One common question that has often been raised is how whales manage to eat underwater. Let us learn more in this regard.

Whales can eat underwater because they actively use their muscles to shield their respiratory tract when they take in food. Baleen whales, in particular, gulp down large quantities of water. However, instead of swallowing it, they place their tongue on their mouth’s roof and push back the water into the ocean after deriving their food.

This method of food consumption is feasible for all aquatic animals as it forms a clear distinction between their digestive tracts and respiratory tracts.

How many krill do whales eat?

Image Credits: “Krill” by pallter is marked with CC BY-SA 2.0.

Curious to know how many krill whales manage to eat? Allow us to tell you more in this regard.

Whales can eat around 3.8 to 4 tonnes of krill per day. On average, this is around 80 tonnes of food per day. While this might seem massive to us, it is important to remember that whales are large animals that need sufficient quantities of food to grow and thrive. 

As such, they need more calories than humans to survive the fluctuating climate in the ocean and sustain themselves.

How many birds do whales eat?

Whales eat birds too. Let us together explore how many birds whales can eat.

Whales, in particular, toothed whales also eat seabirds and seals, sometimes even when these animals are bigger than them. This is because toothed whales eat indiscriminately and do not really differentiate between their prey. However, it is not easy to pin down the exact quantity of birds they can eat in a day. 

How does the blue whale eat?

The blue whale is among the most fascinating species. Allow us to tell you how they eat.

The blue whales, as we have mentioned earlier, are baleen whales. This means that they do not have teeth and have baleen plates instead. As such, krill forms the major part of their diet. They eat by taking in large quantities of water and filtering the krill with the help of their baleen plates. After deriving their food, the water is pushed back into the ocean.

Blue whales, as some of you might already know, are one of the largest ocean animals. Therefore, they can easily eat around 4 tonnes of krill per day. 


Needless to say, whales are intriguing animals with unique behavioral patterns and diet requirements. Over the years, whales have been subject to massive exploitation for commercial gain. As such, several measures have been taken by environmentalists and government bodies across the globe to ensure the preservation of this animal. Whales form an important part of the aquatic ecosystem and help maintain a healthy ocean environment by eating krill and plankton. 


I am Sehrish , I love writing about animals. I like exploring the different aspects of the animal kingdom and aim to present the information to the readers in an interesting, easy-to-read format. The world of animals is full of undiscovered, intriguing facts and stories and there is nothing I enjoy more than delving deeper into it.

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