Ok, I have some game birds that are fully feathered 6-8 mos old and that are in the habit of roosting in a small tree right next to the house. The temps are going into the low 30s tonight, with winds of 18mph. I can catch them and bring them in if need be. Since all my other chickens have been winter layers that go into coops at night, how low can temps go and these birds still be all right? They are semiwild, and mostly fend for themselves.