Lock them in coop for three days before releasing. Install a night light in coop so coop not to dark when they decide to roost. Same affect can be realized by adding an additional window to the west. Make sure they adequate cropfill before going to roost. Versify no external parasite issues although this time of year when very cold that seems not a likely problem.
How old where birds lost to freezing?
How old where birds lost to freezing?
