Water has always been the driving force in East Anglia - its ebb and flow has shaped the fenland. The ancient wetlands once covered hundreds of square miles, but today, well over 90 per cent has been drained and converted into farmland. Every winter, thousands of whooper swans return to the flooded pastures of the Ouse washes from their Arctic breeding grounds. On the Welney Wetlands, spring sees `mad" march hares boxing over mates. It was once thought these bouts were male hares boxing for dominance, but it is often the females throwing the punches to fend off the attentions of over-eager suitors.