How Baleen Whales Function

Quck answer

Baleen whales are filter feeders that use baleen plates to capture and filter food from the water. When feeding, these whales open their mouths wide, taking in large volumes of water and prey. The water is then pushed out through the baleen, while the prey becomes trapped and is swallowed by the whale. Baleen whales also have a unique larynx that allows them to produce low-frequency sounds, which they use for communication and echolocation. These gentle giants are an important part of the ocean’s ecosystem and are a fascinating subject for biologists and researchers.

Wild Animals

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Have you ever observed someone with a large, bushy mustache eating? No disrespect to men with mustaches, but sometimes food can get stuck in there. Imagine if the person did not have any teeth, and that mustache was inside of their mouth. In place of being a disgusting liability when it comes to eating, that mustache would be a beneficial asset for trapping food.

It is a substantial stretch to envision a man with a mustache for teeth, but it should not be a stretch to imagine a whale with a mustache for teeth because that very combination exists in the wild. Instead of having shiny white teeth, baleen whales have plates with rough bristles that resemble a broom. Whales are classified into two groups, the odontoceti, which have teeth, and the mysticeti, or baleen whales. In Greek, mysteceti means “mustachioed whale,” while odontoceti means “whale with teeth.”

There are other differences between baleen whales and toothed whales:

• Baleen whales possess two openings in the blowhole, whereas odontoceti have just one.
• Baleen whales move at a slower pace.
• They usually have a smaller dorsal fin (if they have one at all).
• The mustachioed whales are bigger than the toothed whales.

However, the most important difference is how and what they consume.

While toothed whales are predators that prey on squid, seals, sea lions, and sometimes other whales, baleen whales engage in filter feeding, which is a method of consuming many small pieces of prey at once. These whales feed on krill, which are tiny crustacean-like organisms, schools of small fish, or plankton. They filter these items out of the water with their specialized feeding plates known as baleen.

It may sound like a weak diet for something as massive as a whale, but with each mouthful of water, these whales can filter out thousands of prey items, sometimes consuming up to 4 tons of food per day [source: Marine Mammal Center].

Toothed whales include killer, sperm, and beluga whales, as well as all dolphins and porpoises. So, which whales have these hairy mouths? Find out on the next page.

Types of Baleen Whales and Anatomy

Early baleen whales began appearing around 30 million years ago [source: Carwardine et al.]. Now, there are 11 types of baleen whales divided into four different families:

Baleen whales are divided into four families: Eschrichtiidae or the gray whale, Balaenopoteridae or the rorqual whales (including humpback, blue, fin, sei, Bryde’s and minke whales), Balaenidae or the right whales (including bowhead, northern right and southern right whales), and Neobalaenidae or the pygmy right whale. Baleen whales are similar in appearance to other members of the Cetacea order, with flippers, blowholes, and a tail made up of two flukes. They lack vocal cords but are still able to make sounds. Baleen whales are some of the largest animals in the world, with the blue whale being the biggest and the pygmy right whale being the smallest. All baleen whales practice filter feeding, but the rorqual, right and gray whales use different methods.

What Do Baleen Whales Consume?

The humpback whale reveals its flexible throat grooves.
Mike Parry/Minden Pictures/Getty Images

Baleen whales engage in filter feeding, using their baleen plates as tools. These plates are made of keratin, the same material found in our hair and fingernails. The baleen plates are worn down by the whale’s tongue, but they grow back like fingernails. Whales have hundreds of baleen plates, with the humpback whale having 400 plates that are 25 to 30 inches long, 13 inches wide, and less than 0.2 inches thick [source: MacMillan].

The plates have bristles on one side, resembling a fringed mustache. These bristles vary in length and thickness, but they all help whales capture small fish, krill, and plankton. These prey items are abundant in colder waters, and the large size of the baleen plates allows them to take advantage of the plentiful prey and store energy. The larger baleen whales consume approximately 4% of their body weight each day [source: SeaWorld]. Each type of baleen whale has its own prey and method of obtaining it, meaning that one filter does not feed all.

Right whales filter feed by skimming the water, swimming along the surface with an open mouth. As the whale swims, water rich with the plankton that live on the ocean’s surface enters its mouth.

Rorqual whales gulp food, taking big swallows and filtering out excess water. Their throat grooves expand so much that they can take in about 18,000 gallons (68,137 liters) of water, equivalent to a school bus. The rorqual whale descends several hundred feet below the surface, swims fast, and opens its mouth. The grooves, which are pleated like a skirt, expand so that the mouth forms a huge sac, like a parachute. Although this allows large amounts of prey to enter, it also creates tremendous drag on the whale. One mouthful more than doubles the whale in size for a few seconds and makes it weigh more. When the whale closes its mouth, the water is filtered through the stringy baleen before it exits the side of the mouth.

A fin whale, a type of rorqual whale, can trap about 20 pounds (9 kilograms) of krill with each mouthful. These whales may hunt for about four hours a day to consume 1 ton of krill, offsetting the energy loss from each lunge. The blue whale, on the other hand, needs about 2,200 pounds (1,000 kilograms) of krill to fill its stomach.

The last method of feeding is sucking, which gray whales practice. The gray whale swims on its side on the bottom of the ocean floor and consumes mud and dirt like a vacuum cleaner, consuming up to 20 hours a day and leaving craters behind after a meal. From the mud and water, the gray whale filters tiny crustaceans through its baleen.

Learn about the lifestyle of baleen whales, including their migration patterns and breeding habits. Baleen whales must consume large amounts of krill, fish, and plankton in the summer to prepare for their long migratory journeys to warmer waters in the winter. During the breeding season, males compete for the opportunity to mate with females, while females eat more to store energy for their calves. Whale births are rare, but the calf quickly gains strength by nursing frequently and consuming milk high in fat content. Meanwhile, adult males lose significant weight during the breeding and migration season due to lack of feeding opportunities.

On the following page, you can discover if there are any threats to the baleen whale calf after it is born. Baleen whales are typically too large to be threatened by predators, but killer whales and large sharks may pose a danger. In contrast to toothed whales, which form social groups to protect each other from predators, baleen whales are less social and only have a strong bond between a mother and her calf. When attacked by a larger whale, humpback whales thrash around, while Bryde’s whales try to outswim their attacker. Commercial whaling has been a significant threat to baleen whales for centuries, with right whales targeted for their blubber and oil. Baleen plates were also used in various products, such as corsets, hoop skirts, and whips. While the International Whaling Commission has banned commercial whaling, some exceptions still remain. In addition to whaling, baleen whales can become entangled in fishing nets or be struck by boats. The lifespan of baleen whales is unknown, but it is estimated that blue whales live for 30 to 90 years, and fin whales live for 90 to 100 years.

Additional Information

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• How does the Georgia Aquarium operate?
• Interesting Facts about Walruses
• How do Sharks Survive?
• The Unique Characteristics of Narwhals

More Useful Links

• The Shark Guide by the Discovery Channel
• American Cetacean Society
• The International Whaling Commission
• Marine Mammal Center

References

• “Baleen Whales: A SeaWorld Education Department Resource.” SeaWorld. 2002. (May 12, 2008)http://www.seaworld.org/infobooks/baleen/home.html
• Brewer, Duncan. “Baleen whales.” Mammals. 2003.
• Carwardine, Mark, Erich Hoyt, R. Ewan Fordyce and Peter Gill. “Whales, Dolphins & Porpoises.” The Nature Company Guides. 1998.
• Clapham, Phillip J., Sharon B. Young and Robert L. Brownell Jr. “Baleen whales: conservation issues and the status of the most endangered populations.” Mammal Review. 1999.
• Ellis, Richard. “The Book of Whales.” Knopf. 1987.
• Evans, Peter G.H. “The Natural History of Whales & Dolphins.” Facts on File Publications. 1987.
• Heyning, John E. “Masters of the Ocean Realm: Whales, Dolphins and Porpoises.” University of Washington Press. 1995.
• MacMillan, Dianne M. “Humpback Whales.” Lerner Publishing Group. 2004.
• “Mysticetes-Baleen Whales.” Marine Mammal Center. 2008. (May 12, 2008)http://www.marinemammalcenter.org/learning/education/whales/mystic.asp
• Zimmer, Carl. “Fin Whale at Feeding Time; Dive Deep, Stop Short, Open Wide.” New York Times. Dec. 11, 2007. (May 12, 2008)http://www.nytimes.com/2007/12/11/science/11gulp.html?pagewanted=all

FAQ

1. What are baleen whales?

Baleen whales are a type of marine mammal that belong to the suborder Mysticeti. They are characterized by their long, filter-feeding baleen plates that hang from their upper jaws, which they use to strain small prey from the water.

2. How do baleen whales feed?

Baleen whales feed by taking in large amounts of water and then filtering out small prey such as krill, plankton, and small fish through their baleen plates. They do this by opening their mouths wide and using their tongue to push the water out while trapping the prey against the baleen.

3. How big can baleen whales get?

Baleen whales are some of the largest animals on Earth, with the blue whale being the largest known animal to have ever existed. They can range in size from the smallest baleen whale, the pygmy right whale, at around 21 feet long, to the blue whale, which can reach lengths of up to 100 feet.

4. What is the lifespan of a baleen whale?

The lifespan of a baleen whale can vary depending on the species, but they generally live between 60-90 years. However, some species have been known to live for over 100 years.

5. How do baleen whales communicate?

Baleen whales communicate through a variety of vocalizations, including songs, clicks, and whistles. These vocalizations are used for communication between individuals and for echolocation to locate prey in the water.

6. What is the migration pattern of baleen whales?

Baleen whales have a seasonal migration pattern, traveling between their feeding and breeding grounds. During the summer months, they migrate towards the poles to feed in the nutrient-rich waters, and during the winter months, they migrate towards the equator to breed and give birth in warmer waters.

7. What threats do baleen whales face?

Baleen whales face a number of threats, including climate change, pollution, entanglement in fishing gear, and hunting. Several species of baleen whales were hunted to near extinction during the whaling era, and even today, some countries continue to hunt them for their meat and oil.