According to Eckert's “A Birders Guide to Minnesota” (which is an excellent book and a great read), Black Duck is uncommon in Southeastern MN in winter: so good luck searching the ducks!
Also from this book:
Iceland Gull is difficult (barely regular), black-backed gulls are rare but regular. The west side of Lake Calhoun in the evening is a possibility; landfills in Inver Grove Heights (117 Street E west of Hway 52/55) and Burnsville (Washburn Ave) may be worth checking too.
Long-eared Owl can be searched in conifers along CR 18 between CR 101 and Hway 169 or at Acacia Park Cemetery.
Carolina Wren is virtually impossible.