Blue Jays have saved me at least three times now. Yesterday I heard Blue Jays going off big time. Went out and saw a hawk fly off from just above my pen. Two other times I heard the Blue Jays going off big time, and watched to see them harassing a Fox. Over the years I have watched them harass snakes, cats even people. This time of year they seem more obvious. I guess its bacause they have no young in the nest. Our chickens make the warning or stress call when they are being attacked. It seems Blue jays do it when ever they see a preditor. Heres an Idea; Use nature to help protect your flock!