THEY POINT

Several years ago, scientists diving on the Great Barrier Reef spotted groupers behaving very strangely – they were doing headstands and shimmying their bodies. A team of diving scientists patiently watched many groupers doing this before finally working out what was going on.

When a grouper chases a smaller fish into the reef, usually it’s too big to follow. So the grouper waits for another hunter to pass by, often a moray eel, then does a headstand to point to where the prey fish is hiding. Many times, scientists saw eels responding to a grouper’s gestures by sliding into the reef and either catching the prey or scaring it out of the reef and into the grouper’s waiting jaws. A grouper and an eel will often set off on a hunting spree together across the reef. This is the first known case of fish forming interspecies hunting partnerships and pointing to each other. Using gestures like this is uncommon in the animal kingdom, and it’s thought to be an important prerequisite for the development of language in humans.