Whew! This was a touch challenge huh? There were so many great shots entered! I think that you have a great silhouette here. I really don't think that the color you added in the background added to the picture. Of course I haven't seen the orginal so it may have been an improvement. Your title is confusing to me because the bird is what is one legged and there isn't even a sunset present. Even though your photo is nice, I think that for this challenge it was just lost in the many good entries.
This is a nice picture, but I think you are facing some steep competition. I did want to compliment you on your border though - nice use of the picture as the border - very clean and simple, I'll have to remember to try it sometime. Nice shot.