They are all outstanding.
The males are just so much more photogenic with their brighter blue. I would think you could do something about that in post
Eric
That post looks like a popular perch; you used it well to catch Mr. and Mrs. in great poses. Detail, colors, background, composition all look unsurprisingly stellar to me. My favorite is the last one; that's such an endearing and unique pose. It looks as though she's offering the caterpillar to you!
(Around here, all we have are boring Eastern bluebirds).
~ Ron 
