Hi There,
I would just add that there are so many different ways people choose to "manage" their chickens. For example, me and my 2 neighbors all keep chickens. We all live about a mile from each other. We also all live in the middle of many thousands of acres of forest in the middle of nowhere in southern Kentucky. So, we all have the same set of predators that want to eat our chickens! I like to imagine them going from farm to farm, trying to get at each of our chickens in turn! We all free range during the day. We all have dogs. But that is where the similarities stop. Here's the 3 different ways we manage our chickens:
1. Mine: I free range during the day and have 3 dogs. My 3 dogs are inside/outside dogs. The dogs stay outside for the better part of the day but sleep inside. My barn and chickens are about 1/4 of a mile from my house and I can't see it from the house. So, unfortunately, my dogs are not always with my chickens during the day as they tend to stay wherever I am. If I'm at the house, my dogs are too. If I'm at the barn, they are too. The dogs are pretty good at running everything off that comes in the area which is very helpful. One of the dogs is an Anatolian Shepherd guard dog and he's AWESOME at running the woods regularly to check for predators. I have a predator proof (as much as I could make it) coop that I lock the chickens in religiously every night. See my "My Coop" link under my name for details on how we built it with predator deterrent features in mind. So, the point of this is my biggest predator risk is during the day, especially early morning or late evening.
2. Neighbor 1: He free ranges during the day and has 2 dogs. At night, he has a very insecure coop where he sometimes locks the chickens and sometimes, leaves the door wide open. His coop is close to his house, within sight of it. His advantage is he has 2 Pyrenees dogs that stay out all day and night so they keep the predators away. He did have a snake take 5 of his 6 chicks recently but hardly any coop is snake proof.
3. Neighbor 2: She free ranges during the day and has 3 dogs. She has no coop, nothing. The chickens just run around and roost in the trees. She has 3 dogs that I believe stay out all night and day. She said the other day "Something keeps getting my chickens." In general, she seems at ease with the loses and seems to accept the losses as part of the trade off with the ease she has of having chickens.
I guess my point is just to share that people are different and do things their own way with a different combination of factors and risk tolerance. I'm not really sure it's "common practice to keep hens locked up in their coop at night." It may be more common for people who participate and post in this forum to lock their chickens up at night. But if I were to guess, I'd say many, many people who keep chickens on rural farms do not secure their chickens at night. They may not have runs or fences either. Just a different way of doing it.
Guppy