Animal Groups

Why Do Animals Live in Groups?

Word of the Week

Gregarious

Gregarious animals live social groups.

Some gregarious animals, like ants, live in large groups where each individual has a job. Other gregarious animals, like flamingos, typically keep to themselves within the group.

BRAIN BLAST

Make a list of 10 gregarious animals. Select one of the animals from your list to learn more about. What kind of social structure do they have?

Species Spotlight

Orca

Orcinus orca

Orcas, also known as killer whales, are not actually whales! Orcas are the largest species of dolphin. They are well-known for being one of the most powerful predators in the ocean. In fact, orcas are apex predators, meaning they are at the top of the food chain. Orcas have no natural predators, but they are predators to many. They feed on fish, stingrays, sharks, seals, and even other dolphins.

One of the many reasons orcas are so powerful is because they hunt as a team. They live in groups called pods that are led by dominant females. Orcas are highly intelligent and communicate with sounds like clicks, whistles, and squeaks. This allows them to make well-thought-out attacks on prey.

Orcas have different hunting strategies based on where they live and what they eat. In the Arctic, orcas “spy hop” to find seals resting on sea ice. Then, they swim as a group to create a wave that knocks the seal into the water.

When feeding on schooling fish, orcas release bubbles to drive the fish into a tight ball. They smack the fish with their tail to stun them, then easily catch and eat them.

When hunting larger prey like dolphins or sharks, they ram into their side to injure or stun them. Orcas have been seen killing great white sharks with this strategy! Orcas are nearly unstoppable thanks to their incredible intelligence and ability to communicate with their pod.

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Watch: Orcas Hunting Seal

*Warning: Video shows orcas catching seal.*

Conservation Corner

The Dangers of Living in a Group

Living in a group is an important survival strategy for many animals. Animals like antelope, flamingos, and fish live in large groups to lower the chances of being caught by a predator. If a fish lives in a school of 100 fish, they are less likely to get eaten than if they lived alone.

Living in a large group helps animals avoid natural predators. However, it puts some in danger of being captured by a highly intelligent animal with tools and weapons... humans.

Humans have tools to collect lots of animals at once. This becomes easier when the animals are in a group. One animal that frequently falls victim to this is fish. Fish are being caught by humans at a rate faster than they can reproduce, causing their population to get smaller and smaller. We call this overfishing.

Humans use many different tools and methods to catch fish. To catch fish that gather in schools, large nets attached to ships are dropped around the school. This allows fishermen to catch most of the school at once. It would be impossible for natural predators like sharks and dolphins to catch fish this many fish this quickly. Removing this many fish at once can disrupt ocean food webs as many ocean predators rely on schooling fish for food.

You can make a difference! Make sure any non-farmed meat you eat, especially seafood, is caught sustainability without using any of these disruptive methods.

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