Mating rituals of endangered great bustards

Dawn over the marshes in eastern Germany - the air is filled with a strange sound - great bustards. The males are getting ready to for their annual courtship displays. Great bustards were once widespread across Germany, but nearly became extinct in the last century. The large birds weighing 18 kilos were once deemed to be big game and were hunted by kings and nobility. Today there are barely a hundred birds left in the wild, all of them found in pastures and meadows to the west of Berlin.

It's spring and the males have congregated on courtship arenas to attract the females. Their flamboyant plumes are designed to impress and they pump up their chests for greater effect. The strutting and posturing soon brings in the ladies, who move around the arenas, inspecting the rival suitors. The large gathering of birds has also attracted a less well-meaning visitor. Although the fox is unlikely to tackle an adult bustard, the birds are taking no chances.