How do alarm calls help groups of animals avoid predators?

Alarm calls serve as a vital communication tool in animal social groups, helping members avoid predators through two primary strategies: flee alarms and assembly alarms.1

• Flee Alarms: These are used when animals are in immediate danger. They are designed to be difficult for a predator to locate, often consisting of long, high-frequency whistles with gradual onset and offset. These signals prompt group members to disperse rapidly and seek shelter or protected sites.12
• Assembly Alarms: These are used when animals are dispersed and need to coordinate a joint response, such as mobbing a predator. These signals are typically louder, repeated, and modulated to indicate the level of urgency, allowing group members to locate the sender and gather for collective defense.31

Beyond these specific types, alarm calls help groups by coordinating escape maneuvers, confusing predators, and providing critical information about the type, identity, or habits of a predator. While alarm calling can be risky for the individual sender, it is often considered an altruistic behavior that may evolve through kin selection or provide mutual benefits in shared vigilance.2