I'm not sure why I'm thinking vireo on this one. Photos are pretty dark even after I brightened them up. Pic 1 of 2.
Type of vireo?
This was in the Black Hills of South Dakota. There were a ton of little birds in this one pocket of the trail. Photographed with this bird were a Golden-crowned Kinglet, a Ruby-crowned Kinglet, and an Audubon's Warbler. I'm sure there were also lots of nuthatches b/c they were everywhere, and a type of thrush flew by and into some brush but I did not get a good look at it.
Yep, a vireo. Possibly Bell's, possibly Blue-headed, can't be sure which.
Resin
