This week's quiz bird is widespread thoughout most of North American in wide open spaces and avoids wooded areas. There are an amazing 21 recognized subspecies of this bird (National Geographic Complete Birds of North America) and so this might not look exactly like one in your area.

Last week's tough Empidonax flycatcher was the Least Flycatcher. The other common empid in the northwestern part of North Dakota would be the Willow Flycatcher, slightly larger (though impossible to determine in the field) and with a thin, faint white eyering versus the bold white eyering on the Least being the major fieldmark to look for to determine the species. Habitat is also a consideration with the Least prefering deciduous woodlands with a brushy understory where the Willow prefers brushy areas at the edges of meadows or pastures. For those in the east and in Canada the Alder Flycatcher (among a few others, probably) comes into the fray to help confuse the issue.

(Thanks! to everyone who submitted an answer.)