Finally was able to get out with the D810 and capture some birds in flight. I'm going back and forth on using D9 and Group focusing, happy with both modes.
D810 w 500 f/4 AF-S D ~ Exif Intact ~ Handheld
Kirk (Really happy to be able to join this thread )
Mallard Hen ~ 1/3200s f/5.6 at 500mm ISO400 Manual