France is an important host country for the common cranes (Grus grus) to stop over or to winter. The Lac du Der-Chantecoq, between the Marne and Haute-Marne departments, welcomes around 250,000 of them during migrations. While flying, the common crane calls about every ten to fifteen seconds. The loud trumpeting sound can be heard up to 1.5 miles away (4 km) due to an anatomical peculiarity of the crane's wishbone. Courtship rituals begin in February in the wintering areas. With its wings half-open, the common crane walks with quick and short steps, circling the ground.