Originally posted by plantej I applied just a touch of post editing for the first time with LR.
Apply more.
In this example, the background is more contrasty and full of rough detail, more so than the actual bird. This makes the bird appear almost out of focus. I think you could have shot this one wide open, so that, as you already noted, DoF/bokeh would help you isolate the subject. Shoot in burst mode and delete the photos where you have motion blur or the bird is in an unattractive stance. Get closer. Get lower.
Since you shot at 450mm, the bird must have been pretty far, so reflectors or flash would be difficult, but that could help you with the light. Yes, noon sun does make things look flat and washes out detail. The best you can do against that is watch your angle, move around, maybe put bird feed in an area with better lighting
Technically, your photo is fine, but you notice that it could be better, so you are on the right path. You just need to figure out these little things. For example, how to add sharpness and clarity to the subject, but keep it isolated from the background. What the best sharpness settings are (radious, detail, masking). How to get white balance that brings out detail and makes the subject look alive, and so on. You have some great gear and at the level that you are aiming for, that is what makes the difference. A hundred little things.