Keeping safe against natural enemies
The waters around Madeira are relatively safe for whales and dolphins, since there are normally no natural enemies around. Only very rarely we spot a potentially dangerous shark or orca. Dolphins keep safe against enemies by sticking together in their group. Every dolphin in the group uses echolocation, or sonar, which makes it easy to detect any potential dangers approaching. However, if sharks approach from behind, dolphins tend to be unaware, because their echolocation only works towards the front. Even when an enemy is near, though, dolphins often escape safely. They stick together in their group, coordinate their behaviour, and so act as one big animal. Often, they will make loud sounds, and if the shark doesn’t retreat, even swim aggressively towards the shark in their united group. Even though it is rare, there are even accounts of dolphins killing sharks out of self defence by repeatedly ramming them with their beaks. Sharks therefore mainly fear dolphins when they are outnumbered, and might think twice before attacking a pod of dolphins.
by Judith Kok