We have had a difficult year with preds. Nothing last year, but this year has been much different. First, I live in a subdivision and "free range". By free range, I mean that I have a fully fenced yard (4 foot chain link), but there is no run and they have the whole yard to range. Second, I would say raccoons, but I have not lost any to them. I have trap and/or killed 6 of them in the last 4 weeks. I lost 2 chicks to a cat. It climbed my chicks enclosure, I was letting them partially go out into the yard, but they were double protected, the chain link fence and then another chicken wire fence around their coop. Then I lost 1 chick to the neighbors dog, in the neighbors yard. I took down the extra enclosure, as I thought they were big/smart enough to not leave the chain link area, but they did. They went into the yard of my neighbor behind me and their dog killed one and injured another. The injured made a full recovery.
I have built my coop(s) very secure. I look at it this way, if I am going to put the lives of these birds in my hands, I am going to take it seriously and not take any short cuts. You can see my coop and the ways I have done this by clicking on the link in my signature and going through the process of the build.
Sal