Visitors at the bird feeder....
House Finch (male)
From left to right:
female House Finch, male House Finch, Black Capped Chickadee (how do we know it isn't a Carolina Chickadee?), and Whitebreasted Nuthatch (top)
If this stinking computer had a good photo editor, I would have cropped the second photo better.
You can see how the Whitebreasted Nuthatch came by its nickname, the "Upsidedown Bird." Nuthatches are, I'm pretty sure, the only birds able to walk head-first down a tree.