Do Whales Swim in Groups?

Whales are the largest creatures on earth, and while not all of them are bigger than a school bus, few would argue that any of them are less than majestic. While they are all to some extent social animals, they do not all spend their entire lives in groups. Some do, in fact, spend their lives in groups, but others are much more solitary.

Types

There are two general types of whales: the toothed whales and the baleen whales. The toothed wales come in all sizes, from the relatively smaller belugas to the large sperm whales. With the exception of the sperm whales, the toothed whales were generally not hunted for whaling purposes. Baleen whales are usually large, including the familiar humpback and the largest animal on earth, the blue whale. They are set apart from the toothed whales because as their name suggests, they have strips of baleen (a horny substance) instead of teeth.

Features

Toothed whales hunt their prey, which they catch in their teeth. Their prey ranges from small fish, to seals and penguins, to the giant squid. The baleen whales tend to eat smaller prey, including the smallest organisms in the sea--plankton. They eat by gulping in huge mouthfuls of water and then forcing it out through the baleen. The baleen acts as a sift, trapping the small fish and other food. Both types of whales are mammals, and share common mammalian features such as being warm-blooded and bearing live young.

Significance

The two different types exhibit very different grouping behavior. The toothed whales are most commonly found traveling in groups, which are called pods. Orca (also known as killer whales) hunt in packs, like wolves. The baleen whales tend to be more solitary. Although they may come together for breeding they spend the rest of their lives traveling alone over vast expanses of the ocean. Occasionally they may work together to trap schools of fish, a behavior that has been seen with humpback whales.

Time Frame

Toothed whales live together and hunt in groups year round. For the baleen whales breeding is the only time of the year when social interaction occurs. Breeding groups are short-lived, often for a matter of weeks. Females then raise their young on their own. These whales may also come together at times and locations when there are large swarms of krill, plankton or other prey. This is more of a circumstantial grouping than a social one, and the group disperses once the prey is gone.

Function

Toothed whales, despite their smaller size, eat bigger animals and may benefit more from cooperation. For example, orcas have been known to attack much larger whales, something an individual orca could not do. Even when not hunting large prey, working in groups may provide more opportunity for successful feeding. Baleen whales, on the other hand, do less active hunting and may be thought of almost as grazers. A large social group offers little advantage, and would probably only increase competition over feeding sites.

Resources

• Whale facts and species