Winter Roost Boxes. Chickadees, owls, and woodpeckers that remain in Alaska during winter use natural tree cavities and birdhouses as roosting sites. These roosting sites provide protection from wind and snow and extra insulation against the cold. Any birdhouse can provide a winter roost site if it is properly built, but better insulated birdhouses can also be constructed. Try placing perches on the inside of a birdhouse. During severe cold several chickadees sometimes share their body heat by roosting together in a single cavity.
Use the proper materials. Wood is the best material for birdhouses. Other materials (like metal or plastic) may not insulate the nest enough, so eggs or young could become chilled in cold weather or overheated in warm, sunny weather. Use rough_cut wood slabs, tree sections, or 3ǚ_inch plywood. Never use creosote_treated wood as creosote may kill the eggs or chicks.