Many bird lovers either purchase or build nest boxes for their favourite wild birds: bluebirds, swallows, chickadees, nuthatches and many more. These boxes vary in size and shapes and in particular, the size of the entrance hole, depending on the desired species. We have had as many as 40 swallow houses on our property, and an equal number of bluebird houses on fence posts along the sides of the roads in our area but only after receiving the permission of the landowner.
These nest boxes or houses and their residents provide great pleasure for us during the nesting season, and during the winter as well! Many of “our winter birds” search out these nesting boxes for warmth and protection from predators and the elements on cold winter nights.
Some species of birds will roost together in a colony. We have counted as many as 12 Eastern bluebirds crammed in a single, small nest box during a cold snap in the late fall before they migrated south. Nuthatches will also come together to roost in a similar manner. Chickadees on the other hand roost individually in much smaller confines.
Nesting boxes however are not the best accommodation during cold winter nights, as most are built to allow good circulation and ventilation during the hot nesting season. In winter then, these nest boxes are very drafty and do not retain any body heat from the birds in the enclosure.
A much better idea is to either build or purchase a structure especially suited for winter use–a roosting box, which is designed to retain heat and avoid drafts. These roosting boxes can be as plain or fancy as you like, depending on your creative bent! It is best however if the box is much higher than a nest box–18-25″(46-64 cm) high boxes are ideal. Entrance holes are placed at the front bottom rather than at the top, so that warm body heat will rise to the inside top. Dowels are inserted in the walls in an offset pattern to accommodate roosting and to keep droppings from falling on any bird below. Any cracks in the exterior can be caulked or filled to keep the inside warm air from escaping. Although many birds do die during the cold winter months, the chances of survival are greatly increased if birds have better shelter.
Full plans can be found on the internet. I spent a couple of hours one morning last week making this roosting box, patterned after swallow houses I have been building for many years. The materials used were remnants of a recent fence building project.
Look through that lumber scrap pile you have out back. Make a plan, and then invite your children, grandkids or neighbour’s little ones for a bird roosting house building event some Saturday morning. It has all the makings of a great party!
David A. Homer is a volunteer and on the Board of Directors.