As winter approaches do you leave the screen windows on? Of course not! Likewise it’s common sense that if we want our feathered friends to use (and benefit from) the nest boxes we have in our yards, we must winterize them.

First clean out the season’s nests that may have gotten damp, filthy or infested with blowflies or lice. Then, layer 3-4” of clean dry meadow grass in the bottom of each house. Wood shavings can work well too, but don’t use sawdust as it retains moisture when wet.

Second, plug the air vent holes (and drainage holes) in your houses with flexible weather strip. You can get weather strip (Moretite is one brand) in most home/hardware center stores. It comes in a putty- like cord that you simply press in with your fingers and it comes out easily in the spring. If you want to provide even more winter housing, check out the Cedar Bird Roost.

Who will use your house if properly winterized? Downy woodpeckers seem to be one of the most common winter tenants, even though they seem to prefer to carve their own nest cavity. You can tell they have visited when you find some of the feathers they shed. Their feathers are long with very flimsy shafts with gray barbs and a grayish white tip. Chickadees and titmice will sometimes leave droppings and a few feathers behind while bluebirds leave a few regurgitated seeds. It’s not uncommon for 6-9 bluebirds to emerge from one box. Nuthatches and Carolina Wrens are some other common visitors to winterized homes.