Well, to be honest, with all my lenses, the sharpest one is my Macro lens, and all other lenses has that kind of sharpness to a degree even if it is a prime lens and i use high shutter speed, i have many shots where one frame can be very incredibly sharp and next frame is not as sharp or even you feel it is misfocus, so live with it, time after time you will have more keepers, don't expect that you will get sharp shots 100% from all of your lenses all the time, sure if you shoot that bird again another time you will get sharper shot.
And with same your issue, i shoot a lot with my 1DX and 300 2.8IS mk1 for soccer, and most of them when i zoom in or crop or 100% pixel peeping it doesn't look sharp at all, so i didn't kill myself or send my camera/lens for calibration, many told me that it is normal.
Even with my Hasselblad H4D with say 80mm or 24mm i don't see it very sharp at full zoom, sure it is sharper than my Canon shots, but not that razor sharp sometimes unless i use a tripod and shoot at f4-f16 and high shutter speed, but with f2.8 as your shot above, i often can have sharp image wide open unless it is a lens with f1.2 up to f2 and i stopped down to f2.8.