The secretary bird! One of my most favorite birds of prey but in all honesty this photo doesn't do the bird much justice.

First off the cropping could be slightly better, you cut part of the tail off when you could of gotten the whole body of the birds by moving the camera so that the head was closer to the top of the frame. It's a simple mistake and simple to fix in future photos just take a second look at the subject before snapping the photo.

The photo all so looks just slightly over exposed especially on the white feathers. I would adjust my white balance but if you've taken the picture in RAW format you can play around with the expose setting on the RAW converter. It would also make the black and grey feathers look nicer. (I would recommend taking all your photos in RAW as they are easier to edit later.)

I see you've taken the photo at 300mm and an f-stop of 6.3 which leads me to think you were at a zoo or someplace like that but it would have been nice if you could have gotten a closer shot of the bird. If the bird was closer the background could have been a bit more blurred but as it stands right now the secretary bird looks flat against the in focus background. A bit of patience might of rewarded you with a nice shot here.

Hope this helps but in short:
Watch the cropping, check the photo before you hit the shutter.
Check your white balance, take your photos in RAW for easy editing.
Get your subject in closer so you can really take advantage of that low DoF.

The grace and splendor of the natural world is an infinitely varying and undeniably beautiful thing. The power and poise of some of the earths predatory species is a real wonder to behold, case in point, "Secretary Bird."

The regality of this hunter is displayed wonderfully in the shot. One gets a feeling of speed, balance and power looking at the strength of the animal's stance and the sharpness of it's predatory gaze.

Of points to critique, the angle might be just a little bit lower to help the subject dominate the frame more, but otherwise, "Secretary Bird" is a lovely, lovely piece featuring one of nature's surest and most skilled hunters.