You need to see how protection operates here. First, you should never assume only one method is at play protecting your flock and that roosters operating synergistically with their environment can also have a positive role preventing losses. If you have a closely mowed lawn lacking cover or not effective predator repellent / excluder, then pen all the birds up. MOST PEOPLE ARE IN THE GROUP JUST MENTIONED, MOST. Roosters will come to the active defense of hens tending broods the rooster is likely the sire of. He will also actively engage raptors such as Coopers Hawks that target chicks. I have never lost an adult rooster to a Coopers Hawk and have no direct evidence for loosing a hen to one either. When a Coopers Hawk makes an attack run the rooster positions himself between offspring and the hawk while the hen calls chicks up under her. Usually hawk backs down. I have seen roosters pursue hawk that flies into cover and once into a machine shed after young where I could hear flogging but not see it. Hawks retreated in all situations and did not appear to realize rooster was on their tail until into the cover. Based on what I saw a hen do to a Coopers Hawk the other day, the hawk is risking mortal injuring to be flogged by a rooster. When it comes to other predators there is a major dichotomy between roosters and hens. Hens slink into cover or freeze while rooster steps into open, gets rowdy, and shows his colors providing a distraction. Seldom does the rooster engage the latter types of predators but will delay escape effort to just about last moment. Some of my roosters, as a function of breed, can fly very well and that is the method usually employed to escape. Others like American Dominiques are incompetent fliers but do delay retreat from threat potentially buying time for others.
The warning business, Even juveniles do it although males are louder.
Breeds like silkies and polish are visually impaired. Most bantams have combination of size and mental issues making them less effective.
