#1 is perhaps the throwaway of this bunch, with the twig exiting the top of the frame and what appears to be front-focus (the face isn't sharp).
#2 is quite nice. You have good luck with that male cardinal.
#3, I wish the bird's left foot had stayed in the frame, and the black point is too low - I'd like to see more contrast in the bird's body, I assume the dark grey is really black, the colors would pop more as a result.
#4 I really don't mind the composition, it actually tells a bit of a story with them looking opposite directions, and the profile view of the female cardinal is sharp and well exposed. Again though, the black point could be brought in to produce more contrast.
I don't know if you're doing much for post processing, but there are some minor tweaks that could really improve the exposure in these shots.