More Answers On How Birds Survive Winter in Colder Climes

www.perhamfocus.com/news/science-and-nature/4379489-do-birds-shiver

Make Nest Boxes and Don't Harass Snowy Owls

http://ottawacitizen.com/news/local-news/winter-is-bad-news-for-birds-that-forgot-to-fly-south

Roost Boxes Can Be the Difference Between Life and Death in Extreme Cold

http://www.register-herald.com/sports/roosting-boxes-can-be-the-difference-between-life-and-death/article_5bd1fbb6-e04e-5720-80ec-3530a7b99256.html