We lost 2 this summer to hawks...I believe it was the same Cooper's Hawk. Never had a problem before but this year is bad. After the losses we restricted their 'outies' and monitored them when they free-ranged. DH did a fishing-line spider web over the run since we lost one there, and one in the yard. No more losses in the run, but he was outside when the Cooper's came down like a shot and landed on one of the girls and he chased it off. Good news: our girls are now wise to hawks now and watch for them, even listening to the crows and blue jays for warnings and running like h*ll for the coop when they hear the alarm. Bad news: the Cooper's Hawk and now a juvenile Redtail do drive-bys but since we're diligent they're deterred. Both have landed on the run's railings trying to figure out how to get into the run but neither have dared to attempt it. Thanks to BYC for that advice!