All About Whale Diet
A whale diet depends on the type of whale it is and where they live. Filter-feeders, such as the baleen whale, have different size baleen plates and jaws that determine what kind of food it eats. Sometimes a whale diet is determined by the size of its habitat. If a food source becomes in short supply, another type might have to be substituted.
Many whales spend the summers feeding in northern waters with an abundant food supply, and then migrate to the southern hemisphere to breed in tropical waters in the winter. During this time of travel and mating, they eat very little and live off their food stores. When they do eat, they take in very large amounts. For example, baleen whales eat four-percent of their body weight every day. For a whale that weighs 100,000 pounds, that would equal 4,000 pounds or two tons of food every day.
To just take a look at a few examples of the amount in a whale diet, a Blue Whale eats 8,000 pounds a day. A Gray Whale eats 2,400 pounds a day. Scientists say that it takes 660 pounds of food to fill the stomach of a Gray Whale. Any extra food a whale takes in during his feeding season is stored as blubber for use later on when he or she is traveling or reproducing. A Gray Whale will gain between sixteen and thirty percent of their weight during the summer feeding season.
A whale diet is also determined by the manner in which a whale’s head is shaped, and for baleen whales, the shape and size of their baleen plates, which filter their food. Some whales swim right on the surface of the water with their mouths continually open. In this case, the water is filled with tiny zooplankton which they strain out. The food and water goes into the mouth through a space in their baleen plate. The food gets stuck in the fringes on the baleen, and the water goes back into the ocean from the sides of the mouth. This is a whale diet that is obtained by straining. The Right Whale is a good example of a whale that feeds in this manner.
Other whales, like rorqual whales, are gulpers. A Humpback Whale is an example of a rorqual, and it gulps in water filled with large amounts of crustaceans and schooling fishes. They often roll on their sides when feeding. They also have throat grooves which expand to open the mouth wide and let food in, and that contract to allow the water to drain back out through the sides of their mouths.
The Gray Whale diet is different from both of these. Gray Whales suck in water, food, and mud off the ocean floor. That means they eat crustaceans and worms. They have baleens that catch the food and then allow both the mud and the water to escape. The Gray Whale leaves craters in the ocean floor in their feeding areas.