There are a few species of songbirds that stick around for some of the chilly winter months if they are able to stay out of strong winds and have sufficient nutrients. Birds utilize a few techniques to stay warm and like many animals, can slow their metabolism. Birds that may choose to endure winter weather include bluebirds, chickadees, titmice, screech owls and some woodpeckers. For those birds, it’s a good idea to provide roosting boxes, many of which can be converted into bird houses later.
Here are a few tips adapted from The National Wildlife Federation’s website:
Like many people , you may not have the time to build a box from scratch. Many prefabricated boxes are available, most of which come in kits. Bird enthusiasts recommend a box with a larger-than-usual entrance hole—it’s easier for birds to get a good look inside and also easier to enter and exit.
Winterize. If you opt for using your spring nest boxes as winter roosting boxes, you may want to block the large ventilation holes—which keep the summer sun from overheating the interior. Foam weatherstripping (the kind sold for air conditioners) works well, and it’s easy to remove when spring rolls around. It’s also a good idea to face the hole away from prevailing winds.
Consider not sealing the box up tight, allowing birds like to peek inside a box before entering. Birds are reluctant to enter pitch-dark boxes and like to check for danger inside.
Protect the box from predators. Mount it on a metal pole. Tree and wooden fence post mounting makes it much easier for cats, raccoons, weasels and rats to climb. It is possible to lose a nest box full of chicks to (a) predator(s) in one night.
Consider the type of bird you are trying to attract, most boxes are large, fitted with interior perches. If you choose a box with the entrance holes near the top or bottom of the boxes instead of the middle. this allows ample room and less leakage for rising warm air.
If the prefabricated box has a perch, bluebirds don’t need it because they sleep in a heap on the floor. Additionally, if you were trying to attract Bluebirds, utilize a box that has the middle or top whole since they are floor-sleeping birds. A hole at the bottom might make the floor colder and this also allows easier access for predators to reach in and grab a bird. You may also consider using a guard against these predators.
Many people attract roosting birds simply by leaving nest boxes up all winter. Anecdotal evidence suggests roosting birds prefer boxes mounted 10 feet high or more in winter—perhaps because birds feel safer at these heights. There is a tendency to mount nest boxes at eye level to easily check on nest progress. If you do not want to lug around a ladder, use a telescoping pole to put the box in place and take it down for cleaning and re positioning in spring.