I don't let them out at 8AM like I once did on the weekends..... I tend to keep them in til noon or later. I don't know if that matters. I have had attacks at all times of the day over the years. I hate that you let them out and immediately were seeing shadows....those hawks must be hungry down in Texas. There is not much you can do legally about a raptor..... You cannot shoot them. I believe it is even against the law to throw a rock at them. Probably best to avoid them by making your coop larger. You could still let them out, but with the bigger coop, you can let them out less frequently with a clear conscience.... and if they are out less frequently, they will be less of a regular stop for the local predators. Let them out while you are around to watch them. Some people get chicken tractors which are like mobile cages that allow the chickens to get out and about on the grass, while still inside a safe containment. With only four birds, that might be something you could explore.