As usual, you are blessed with keen observation and skills of deduction!!! Love ya, Bee!I'm going to burst your bubble here.....every single bird that I have that has been taken by an aerial predator has been a barred rock. Ranging right next to White Rock of the same age and size, the hawk consistently took the barred birds.
Consider this....aerial preds seek out what looks most like its natural prey and those barred, speckled, flecked and otherwise patterned birds are such as these. Been free ranging white birds in every single flock over 40 yrs time and the hawks never even attempt to nab the white birds or any of the solid colored birds, for that matter.....always, always the barred pattern birds. When the birds duck and freeze, the white birds are just a white blob and you can't even see them breathing, as their "pattern" is all white...could be a rock for all they know and if they ducked under leaves of the underbrush, they are even more invisible. The barred birds, however, show fine movements BECAUSE of their patterns....when vision is black and white and shades of grey, the movement of the breathing of the patterned birds is enough to draw their eye.