Consider using a tarp or shade cloth to obstruct view chickens have when the hawk is purchased overhead. Make certain the additional covering can withstand the weather as related to wind / snow / rain. Obstructing the hawk's view will also make chickens less interesting. It is unusual for a hawk to keep messing around chickens unless it is catching something, like another prey type such as rodents or songbirds. Odds are it will move on shortly.
