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Group Behaviour and Survival

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Why animals live in groups

Many animals live in groups, and group behaviour can increase an individual’s chances of surviving and reproducing. Groups offer protection. With many eyes watching, a predator is spotted sooner, and an alarm can warn every member. In a large school of fish or flock of birds, each individual is less likely to be the one caught. Cooperative hunters, such as wolves and lions, can bring down prey far larger than themselves. Groups can also save energy. Emperor penguins huddle through the Antarctic winter, taking turns on the cold outside edge. Group living has costs, however. Members compete for food and mates, and disease spreads easily.

Cooperation and communication

Group members often cooperate, and cooperation depends on communication. A honeybee that finds food returns to the hive and performs a waggle dance. The angle of the dance shows the direction of the food relative to the Sun. The length of the waggle run shows the distance. Meerkats take turns as sentinels, watching from a high point while others feed. Vervet monkeys give different alarm calls for leopards, eagles and snakes. When researchers played recordings of these calls, monkeys responded with the right escape: climbing trees, looking up or looking down. In ant and bee colonies, most workers never reproduce. Instead, they help their relatives, who share many of their genes.

Curriculum links: NGSS HS-LS2-8 · England KS4: Biology · Cambridge IGCSE: Biology