Looks like you had some pretty harsh lighting to deal with. Wouldn't be so bad, except for the shadows cast by branches on the birds in two of the photos.
The second one is my favorite; that one's really nice!
The first one looks a little soft to me. The last one, the goldfinch, I like except for the OOF branch in the foreground. Not always anything you can do about those branches, and normally I don't worry about them, but that one really distracts me for some reason. Maybe because the buds on it already make it more noticeable than it might typically be, and then being out of focus adds to the distraction.