I don't know if it's different for other breeds but when I raised pekins for meat, I could hear the difference in their voice at the 8-week mark, so 2 months ish.Good to know thanks! They have a nice big area now so they could stay there and be quite comfortable but we will probably create some temporary moveable fencing so they can have other areas to explore but will stay away from the chickens. The chickens rule the property lol Do you know what age they start quaking?