The DNR is searching for whoever has been killing federally-protected trumpeter swans in Minnesota in recent days. At least five of the birds have been shot to death. The DNR’s Rich Sprouse says it’s not easy to mistake a trumpeter swan for a snow goose or other smaller species. Swans are large birds that grow up to six feet in length with a wing span of eight feet. Killing them can bring fines of up to $1,700.