John - if you take RAW images 99% of the time they will need some processing - the in camera software does not apply any "processing" defaults to RAW files (versus) what it does by default to jpegs, (have a look in your camera settings to see what the in camera software applies to jpegs)
When you apply NR it will reduce any detail in the image
If you apply NR to an image, do not apply the same level to every part.... be selective
with an image like this apply NR to every part other than the bird, and the sharpe DOF areas around the bird ....... either by applying NR to all the image and then using a "mask" to bring the bird back to as it was before NR was applied, but there are several other ways of doing this depending on the software that you have
The detail in the young Song Thrush above has been lost either, a), through NR being applied to the bird, b). camera or bird movement, or c). off focus ... as even at f5.6 you would have some DOF to give you a "range" of sharpness, albeit, smallish