Common Cranes (Grus grus) utter a regular scream in flight, a persistent and loud “krou, krou”, which can be heard for several miles around. This scream allows group members to keep up with each other. A single bird will repeat it every 10 to 15 seconds. There were many stories about cranes in Ancient Greece. It is written, for example, that cranes put pebbles in their beaks when flying over the Taurus Mountains in Anatolia, in order to avoid making their usual call and thus attract the attention of their enemies, the eagles