1/7/2020, LOESS HILLS NATIONAL WILDLIFE REFUGE, MO. - Twenty-four image sequence of a Trumpeter Swan pair taking off across an icy marsh at Loess Hills National Wildlife Refuge. This was just after dawn on January 7, 2020. There were hundreds of Trumpeters on the refuge. Because of their weight (20-25 pounds), swans need 100 yards of water to become airborne. The swoosh of their wing flaps and the impact of their feet hitting the water made a distinctive "whap, whap, whap" sound echoing across the marsh as they struggled for altitude.