While birds don’t need us to provide birdhouses for nesting, it’s a fun way to add to your bird-friendly habitat. But it’s not as simple as putting up a box and hoping for the best. Just like us, birds have specific requirements before they move into a new home!
Birdhouses, also known as nesting boxes, should be ready in advance of nesting season. For most North American birds, spring and summer are prime times for raising families. “The peak is March through July, largely due to the impact of warmer weather, longer daylight, increased insect availability, which is baby bird food, and migratory bird arrivals after their long journeys from southern wintering habitats,” says Joanna Eckles, Bird City Network Coordinator at American Bird Conservancy.
However, there are variations based on the species.
Some birds, such as owls and eagles, start nesting at the beginning of the calendar year. Other familiar species, such as robins, chickadees, bluebirds, and hummingbirds can start building nests as early as late February. Cardinals, wrens, finches, and swallows tend to build nests in early spring. Coastal species like oystercatchers, terns, and plovers nest around June, says Eckles.
Many types of birds raise more than one family. “Common songbirds including American robins, mourning doves, Eastern bluebirds, Carolina wrens, and northern cardinals raise multiple broods into the summer, taking advantage of abundant food and long daylight hours,” says Eckles.
Ahead, learn exactly what birds like (and don’t like) so you can attract them to your birdhouses:
What Kind of Birds Use Birdhouses?
It may surprise you, but not every species will be attracted to your birdhouse. Cavity nesters are the most likely to be interested in your birdhouse because these boxes mimic the type of habitat these birds like. “Birds like wrens, chickadees, titmice, bluebirds, kestrels, tree swallows, and certain owls, are attracted to nest boxes,” says Eckles. “However, some cavity nesters, such as woodpeckers, make their own cavities in dead or decaying trees, which is why they aren’t usually attracted to nest boxes.”
In fact, most bird species don’t use nest boxes. “For example, you will never see a Northern cardinal, American goldfinch, nor a hummingbird use a nest box, because they typically build their open-cup nests on tree branches,” says Holly Grant, project assistant for NestWatch at Cornell Lab of Ornithology. Other species, such as a kingfisher or burrowing owl, use burrows; floating vegetation is used by birds such as gallinules and black terns; and cliff ledges are used by birds such as peregrine falcons.
When to Put Up a Birdhouse
For most North American bird species, the best time to set up a birdhouse is in winter before they start their breeding activities, which include mate attraction and mating. “Birds need nesting habitat ready to go, not after the fact,” says Eckles. “Many start prospecting for homes in mid-winter.” Ideally, put your birdhouse up by late February in southern regions, March for more northern ones.
However, don’t worry if you didn’t get around to it this year. Ideally, plan ahead for next season by erecting your birdhouses this fall. “This way, the ground is still soft, and there is plenty of time for birds to find them and get used to them in their environment,” says Grant. “Some species may even use them as a sheltered place to roost in the winter, and then by the time spring rolls around, they’ll likely be all set to be seriously considered as potential nesting habitat.”
That said, it’s okay to install boxes in the spring, too. “But be sure to place them a few weeks before your target species begins nesting,” says Grant. “Again, the birds will need to have enough time to find them before they decide where they build their nest, so don’t worry if your spring-installed boxes go unused that first year.”
How to Make a Birdhouse Attractive to Birds
There are many features that can make a nest box attractive to a certain species, but nothing will guarantee its use. “The best thing you can do is add features that make it safe and comfortable for your target species, and hope they will choose to nest there,” says Grant.
A few ways to make your birdhouse feel like home sweet home:
Know what species you want to attract.
“Research the preferences of your target species—mounting it at the right height, pointing it in the preferred orientation, and adding any other features specific to that species,” says Grant. “For example, barred owls, American kestrels, and chickadees prefer a layer of wood shavings lining the bottom of the box.” You can build your own birdhouse with untreated lumber and learn how and where to mount them with these free plans for specific species.
Make sure the entrance hole is right-sized.
“If it’s too small, they can’t get in. If too big, unwanted predators or other undesirable species can get in,” says Eckles. Bluebirds, for example, seem to like boxes with an entrance hole that’s 1½ inches in diameter.
Use predator guards.
Many different predators can make their way into a nest or can reach into it to steal eggs or babies. Baffles, metal flashing, aluminum foil, or greasing a pole that’s used as a mount are all ways to discourage predators, says Eckles.
Give them fresh air.
Don’t skip this step. Drill some ventilation holes to keep air moving without sacrificing critical warmth on chilly spring mornings, says Grant.
Don’t add a perch.
It may seem essential, but it’s really not a good idea. Birds know how to navigate and can enter without a perch. Perches are unnecessary and can help predators reach further into the box, says Grant.
Clean birdhouses at least once per year.
Wait until the end of the season after the birds are done with the box. Remove any nesting materials in the box, and use water and mild detergent if the box is particularly soiled with fecal matter, says Grant.
How to Make Your Yard Bird-Friendly
While feeding the birds a variety of foods and providing nest boxes or birdhouses are good ways to help support your backyard birds, it’s even more important to create a welcoming habitat by following these tips:
Add native plants to your landscape to provide food and shelter.
In spring, many “birdfeeder” birds will become more reliant on protein-rich invertebrates such as caterpillars and grasshoppers for feeding their young. “Eastern bluebirds can consume up to 2,000 insects in a single day, while Carolina chickadees need more than 6,000 caterpillars to successfully feed and raise five chicks,” says Eckles. “Many insect species are adapted to particular native plants. Without those plant species, you won’t have the insects.”
Provide a variety of plant species.
This supports insects that birds eat. But it also increases nesting opportunities for those species that don’t use boxes, says Eckles.
Make your garden a pesticide-free zone.
“Overuse of these toxic chemicals depletes the insect populations birds depend on, poisons prey that birds ingest, and can cause direct danger or death to birds,” says Eckles.
Protect birds from window collisions.
More than 1 billion birds die each year from colliding with glass—almost half of those on home windows and low-rise buildings. Birds can’t see glass, and the reflections of sky and trees make it even more dangerous for them. Many commercial and DIY solutions can prevent these collisions: Use window screens, apply tempera paint patterns, or place adhesive decals spaced 2 by 2 inches apart, says Eckles.
Keep pet cats indoors.
One roaming cat can kill dozens of birds per year, especially helpless chicks and fledglings, says Eckles. Keep your fur baby indoors (which is safer for them, too).
