My roosters certainly crow at night, I also run lights in the early morning to keep the girls firing. If I go out I can hear many others crowing as well. Who started it, who knows, but each one is going to be the last one to crow, LOL. But it seems to me it is an "all clear" signal, as in no predators spotted. Now if one calls a warning in the night, I am out the door with a gun! (I am in the country, more or less, my place is 1/4 mile square)
My neighbors are all methheads, and I no longer give a rats behind as to what they think. I hope to have better when I move!