Want to install a barn owl nesting box on your farm or ranch? Choosing the right design is crucial. If your goal is to attract barn owls for mice control, you need a nesting box that is both safe and comfortable.
Our detailed guide will help you find the best barn owl nesting box design for your property.
What Makes a Good Nesting Box Design for Barn Owls?
If you want to attract barn owls, you must have a suitable nesting box.
The Barn Owl Trust provides some excellent advice on what to look for when choosing a barn owl nest box design.
Bigger is Better
When choosing a nesting box design, one of the most important things to consider is the size. Barn owls stay in their nests until after they are fully grown, so you need to make sure there is plenty of space for them to fit comfortably.
Keep in mind that these birds are on the larger side, and there may be up to five birds in a nesting box at a time. Young barn owls also like to perform wing flapping exercises inside of their nests, so aim for bigger boxes that can accommodate their needs.
At Least 17 inches Deep
Baby barn owls start walking at an early age, but they can’t fly until they are about 59 days old. During those first 60 days, they are incredibly vulnerable. If your box isn’t deep enough and the baby owls can easily walk through the front opening, they can fall and ultimately die.
The Barn Owl Trust recommends:
A minimum depth of 450mm from the bottom of the entrance hole to the bottom of the box. That is about 17 to 18 inches high. At this depth, the baby birds won’t be able to get out of the nest until they’re about 45 days old.
700mm (27.5 inches) depth for total safety. If you want to ensure that the barn owls cannot leave the nest until they are able to fly, aim for a depth of 700mm.
A deep box is crucial to preventing baby owl deaths during this vulnerable 60-day period. You can make your box even safer by adding an exercise platform right outside of the entrance hole.
Keep it Dry
The third key element to consider when choosing your design is moisture. The nesting box must stay dry, or the eggs may get too cold and fail.
Some nesting boxes are designed for use indoors where rain won’t be an issue. If you plan to keep your box outdoors, make sure the box has:
- An angled or overhang roof.
- An exercise platform that is angled away from the box, or a slatted exercise platform that allows the rain to flow through.
- Weather sealing along the joints to keep moisture out.
Barn Owl Nesting Habits
Like many other birds, barn owls are cavity nesters. In the wild, they prefer to nest in caves, hollow trees, or crevices in riverbanks and other natural areas.
There are advantages to cavity nests: they’re naturally dryer and warmer than open-air stick nests. They also offer better protection from predators and wind.
To encourage barn owls to nest in your box, you need to create a space that’s similar to what they would choose in the wild.
Where to Place an Owl Nesting Box
Where do you plan to place your nesting box: in a tree, on a pole or inside a barn? The placement of the box matters when choosing a design.
Pole boxes should be large with a depth that’s close to (or at) 750mm.
The exercise platform should, ideally, wrap around the entire box to give young owls a safe place to land or wait for food. Because pole barns are out in the open, they should provide maximum protection from rain to keep baby owls or eggs dry and warm.
Tree boxes tend to have a more angular shape that allows them to fit nicely against a tree trunk.
The tree will provide some shelter and protection, but the box should still be deep enough to prevent nest falls. Overhang roofs work well for these boxes. Exercise platforms don’t necessarily need to wrap all the way around the box.
Barn boxes offer virtually no weather sealing because they are designed for indoor use.
Depth and size are still important, so make sure that you’re at least meeting that minimum 450mm or 17-inch depth requirement.
Barn boxes have the added benefit of keeping rodent populations lower inside the barn and away from the animal feed.
Frequently Asked Questions
Around mid-February when barn owls start nesting. All of your nesting boxes should be ready for use by late winter.
Squirrels can easily take over nesting boxes and prevent barn owls from nesting inside.
One way to keep squirrels away is to install squirrel baffles. These are metal discs that wrap around poles and make it difficult or impossible for squirrels to climb up inside.
Baffles can also help protect your nesting boxes from raccoons, snakes, and cats.
Yes. Nesting boxes should be cleaned every year in late fall (late October through November).
Barn owls are least likely to be in your nesting box during this time period, so it’s the perfect time to clean out this space.
Choosing the Best Nesting Box For Your Barn Owls
Size, depth, and moisture control are the three main things to consider when choosing a nesting box design. Providing a safe space for young owls to grow and thrive will help keep the rodent population under control.