Tips for Building Birdhouses
I have always enjoyed building things and birdhouses were a natural here in the wooded rural area of Maine where I live. This area, like a lot of Maine, is still rural but is growing and changing from farmland to a suburb and natural nesting habitat is decreasing.
There are still many areas left that provide adequate nesting sites for many species of birds but, like feeding them, they can always use our help, and it’s fun to build a nest box or shelf. It’s really a thrill when they are used by the birds, especially if it’s the species you intended.
Many birdhouses can be of a similar and simple design with adjustments made for size of cavity and size of entrance hole to accommodate many different species of cavity nesters.
Nest boxes do not have to be made out of clear or high grade wood. Rough-sawn wood is easier for birds to grasp or grip – esp. the young birds climbing to the entrance/exit hole. A hollowed out log makes a very natural nest box when a sturdy floor and roof are added.
The boxes should allow access for cleaning after the nesting season is over. Some designs have a hinged side that swings up or down to permit access. I prefer a hinged or removable roof with solid sides and floor. Roofs are the most often replaced part of the box because of sun, rain and snow so it makes sense to make them easily removable. Roofs can (and probably should) overlap the sides of the box.
Provide plenty of ventilation – space between roof and sides and vent holes drilled in the sides at the top.
They should be left natural, un-painted, un-stained or un-varnished, inside and out. If you must paint, paint it white to reflect the sun and ONLY on the outside. Also, if you must, roofs can be painted, stained or varnished – on the outside or top – to help them last longer. Staining the outside of a nest box is ok as long as you let the stain “cure” properly (for painting, varnishing, or staining, I like to allow one season – put out in the Fall for the following Spring).
Roughed-up insides help the chicks climb to the entrance hole when it’s time to leave. It’s not necessary to rough-up the insides if the lumber is rough sawn.
It’s best to mount the boxes on a pole or sturdy pipe. Boxes mounted on trees will attract squirrels (the Flicker boxes and a Pileated Woodpecker box I built are all mounted on dead trees and never have attracted squirrels – I think they’re too big for them). Predator guards or baffles can be used to discourage raccoons and weasles from climbing to raid the nest box for a meal.