A mallard searches for food on the wetland in Qinhuangdao, a coastal city in north China's Hebei Province, Dec. 30, 2009. A flock of mallards fly to the coastal wetland that has not froze over.  

Mallards search for food on the wetland in Qinhuangdao, a coastal city in north China's Hebei Province, Dec. 16, 2009. A flock of mallards fly to the coastal wetland that has not froze over.