I think of it slightly differently. Chickens 'in the wild' live and die and get injured and get eaten. And that is what it is. However, once any one of us takes on responsibility for an animal we have some level of duty of care. Yours are semi-wild so you duty of care is very different from mine because I introduced chickens into my yard knowing that with all the foxes and raccoons they wouldn't last a minute on their own. So I build a coop and a run (aka Chicken Palace) so I can protect them. Does that make sense to anyone?