Same as Axel. The is too much negative space underneath - a pano crop might work, and the birds need to be sharper. I like the position of the birds though, particularly the almost interlocking ones in the middle!
JP
I played with this image and the pano crop definitely would make a difference. The biggest problem I had was that I couldn't get the cranes sharp enough to keep the viewer from thinking they were OOF. I think silhouettes are very attractive images and you had the right idea. If you get a chance you might go back and try for some more.