MPR's Brent Wolfe has this Mainstreet report on the study of tundra swans. The Upper Mississippi River between Wabasha and La Crosse is a temporary home to as many as 15,000 tundra swans, as they stop off here each winter enroute from their breeding grounds along Alaska's north slope to their wintering grounds on the Chesapeake Bay.

Scientists know a fair amount about swan behavior at the breeding and wintering grounds, but they're just beginning to study where they spend their time on the river and what impact they have on the Upper Mississippi River Wildlife Refuge.