The framing is not the most appropriate, try a vertical format, a little noise in the shadows due to the high iso (800) and a slight blur in the bird's head, you can solve everything by doing a good development
Thanks for taking the time to reply...will submit another photo of the bird in a vertical format and lower ISO!
Tip: if you post another photo, be sure to also tell us the actual reason that Adobe gave you. This will save us from wasting your time with a wrong guess. Good luck!
Adobe gave me no reason for declining it...that's why I was surprised, they just said due to technical issues it wasn't approved! Will see if the new photo also gets rejected or not, thanks for your tip
Technical Issues is the reason for refusal. Take a read through this help file that offers more details.
You also have a couple of sensor spots that need to be cleaned up. They are in the upper right area of your photo against the sky.
thanks so much for spotting that Rob, I'm surprised I missed them and indeed a very valid reason for rejection!