Beautiful bird, and interesting habitat (I'm used to seeing these guys within reeds and cattails). A bit too much room above IMO, and I would darken the midtones as I find the image rather light. Good sharpness for that shutter speed...that wren must have held steady for a second for you!
Here's a case where a busy BG provides a great sense of habitat and a wonderfully complimentary color to the bird. Nicely done. Agree with previous comments about a bit of crop from the top and slightly darker mid-tones. Handsome image.