AS Stuart mentioned, sharp! Nicely exposed, classic Giant's Castle background. From a comp. standpoint, I would prefer a bit more space between the landing bird and the perched ones. Do you have any frames a bit earlier?
"Timing is everything" and you nailed it. Very well-planned to get all three birds in the same plane with adequate DOF at f/6.4 and to freeze the flier's wings with such a fast shutter speed. Exceptional!