Here are the 10 bird species most difficult to see in Minnesota, migrant or resident, as chosen by Bob Janssen, the state's birding godfather. (Thanks, Bob.)

Harlequin Duck
Clark's Grebe
Little Blue Heron
Prairie Falcon
Piping Plover
Bell's Vireo
Mountain Bluebird
Smith's Longspur
Connecticut Warbler
Yellow-breasted Chat