I have noticed that many are having hawks attacking their chickens. One way to slow these attacks down is a simple one. String CDs above the run. For some reason as the CDs move in the wind, the hawks and other birds of prey shy away. This is by no means 100%, but it will cut your loses way down. I have used this method for many years and have had only a handful of attacks. I can sit on the porch and watch the hawks checking out my chickens. As they start for the run the CDs will move and the sun light will shine on them. When the hawk sees this they leave. Something so simple seems to work, most of the time.