I am sorry, but I can't agree with the post above. The pictures are a little blurry with a little or no contrast, have a busy background, dull colors etc.
#1 - is a slightly underexposed and I can't see the details of the bird. Its eyes are completely black and the bird itself is blending to the tree.
#2 - again, bird blending to his background (tree), out of focus and blurry
#3 - overexposed, blurry, out of focus, busy background, colors are completely off on this one
#4 - same as #3 + very uninteresting pose of the main subject
#5 - would be probably the best of the set, however, the bird is out of focus and the picture is slightly overexposed
#6 - probably currently the best of the set, only ruined by its busy background. I find the colors on this one to be better than on the other pictures and the bird has finally it's eye in focus!
Another thing I would want to give you an advice for is, that when you're shooting a set, try to keep the white balance, colors and so on, to be as close as possible. Your every picture differs from all the others in this set.
Hope that makes any sense, English isn't my primary language so I struggle with it sometimes.