Old decaying trees still make the best homes for birds. But gourd birdhouses are a fun and pretty way to increase the available nesting cavities for native birds. Birdhouses hung in early spring are more likely to attract a bird family than those hung later in the season.
Birds prefer entrance holes that fit around them closely and that are too small to let in predator birds. A perch outside an entrance hole aids any predator bird that wants to raid a nest, so it is best not to add perches to birdhouses.
Here are the entrance hole sizes preferred by some New England birds followed by how high the birdhouse should be hung.
Nuthatch 1 to 1-1/4. 6 to 15 feet up
Chickadee 1-1/8. 6 to 15 feet up
Titmouse 1-1/4. 6 to 15 feet up
Swallow 1-1/2. 10 to 15 feet up
Flicker 2-1/2. 6 to 20 feet up
Entrance holes can be drilled with hole saw bits purchased from a hardware store. The bits often come in sets of different sizes and fit electric drills. The curved and slick surface of gourds makes drilling entrance holes a job for grown-ups!
Gourd Dust can harm your lungs.
Work in a well-ventilated area.
Wear a breathing mask or respirator.
Smaller, drainage holes at the bottom and hanger holes at the top also need to be drilled into your birdhouse gourd.
After drilling the entrance hole, you will need to clean out the dried pith inside the gourd. This should also be done initially by a grown-up.
Use a bent wire coathanger to clean the inside. You can also fill the gourd with some pebbles and water and shake to clean out the outside, but then the gourd needs ample time to dry out again.
Before decorating, any undesired bumps can be sanded off and small holes and bug-bites can be filled with wood fill. Gourds can be decorated by wood burning (in a well -ventilated area). They can be stained with leather dyes, or painted with acrylic craft paints. If painting a gourd, it is helpful to seal the gourd first with a coat of acrylic primer. Finish a gourd with a protective varnish before hanging with suede lace or monofilament fishing line.