Build an Owl Nesting Box

If you’re keen to attract owls to your property, one way that is sure to encourage them is to build an adequate refuge nearby. There are numerous books on the topic and various plans available on the Internet, too. Make sure, however, that the box you select is suited for the specific birds you want to attract. The plans we used came from the South African Endangered Wildlife Trust’s Birds of Prey Programme. We made a few alternations on ours for easier construction and lower maintenance.

Owls, like most creatures, are particular about their accommodation. A nesting box for a spotted eagle owl will differ from that of a barn owl for example, so you need to make sure which type of birds occur naturally in your area before trying to attract them.

Barn owls are common residents in most open habitats. They will roost in spaces that are protected and weatherproof, and can generally be found in old warehouses, hollow trees, caves and even mine shafts. Rodents make up a large part of the barn owl’s diet, along with small mammals, birds, reptiles and frogs.

DIFFICULTY: Beginner
ESTIMATED TIME: 3 Hours.
COST: R250.00.
MATERIALS: SA pine: 2 400mm x 455mm x 22mm; 40 x 40mm brass; screws; Wood glue; Wood sealer.We used SA pine for our barn owl nesting box. The largest portion of our construction was made up from a single plank measuring 2.4m x 455mm x 22mm, available from your local timber dealer. To provide additional weatherproofing to the roof, we cut a sheet slightly larger than the roof measurements from a waste sheet of galvanised sheeting. While the latter can reduce maintenance, it’s not an essential part of the construction and can be dispensed with. We also used 40 x 40mm brass screws and wood glue to assemble the owl nesting box, and an exterior marine-quality wood sealer.

Step 1:
Start by tracing the six panels – four walls, the roof and floor – of the construction onto the planks. The roof measures 60 x 457mm; the floor, which incorporates a landing platform, measures 580mm on its longest side and 457mm on the opposite side (see adjoining photograph); the side walls, which will have the top edges slanting towards the entrance, measure 429mm at the high point and 329mm at the lower end; the rear panel measures 450 x 457mm and the roof-side edge must be cut at an angle to accommodate the slanting roof (use a bevel square tool); and the front panel measures 350 x 228.5mm.

This project requires very basic tools: A square, bevel square, drill, power screwdriver, paintbrush, hammer (not essential) and skill saw.

Make sure to work according to your plan when assembling the box. Each side, except for two, is a different shape.

Step 2:
We found a Skil saw the most ideal for cutting them out. Take note that except for two side walls, each component has a different shape and size to suit a specific purpose. This owl nesting box has a slanted roof and a floor that incorporates an extended landing and perch platform. At its highest point, the box measures 455mm. The entrance measures 400mm, which makes allowance for the size of the adult birds (300-350mm) to enter and exit comfortably.

Make sure to work according to your plan when assembling the box. Each side, except for two, is a different shape.

Step 3:
Assemble the components with the glue, which acts as added waterproofing in the joints, and screws. Sand down the box for a smooth finish and use a sandpaper-wrapped block of wood to round off the sharp edges and corners.

A power screwdriver makes light work of assembly.

Use a square tool to make sure your drilling holes are lined up accurately.

Sand down any sharp edges for a neater and more appealing finish.

Step 4:
In our construction we then fixed the galvanised sheet roof cover, painted with an all-purpose undercoat, using a few short screws to keep it in place.

We attached a galvanised sheet to the roof of our barn owl nesting box to ensure protection from the elements.

Use wood glue between the joints to ensure a stronger and watertight construction.

Step 5:
We applied three coats of the sealer to the exterior and entrance area of the nesting box. After the first and second coat, we lightly hand sanded the box each time to ensure the wood is well protected against the elements.

The owl box will be exposed to the elements. It’s worthwhile spending a little extra on a good wood sealer and making sure you have three good coats on the wood.

Sand down the assembled box for a smooth finish.

Step 6:
All that remained was to mount the box outside. Remember, where you place the box is a key consideration, not least of all to determine how it will be mounted.Keep in mind that the presence of a nesting box doesn’t necessarily mean owls will settle there. It needs to be in a position that suits the needs of the bird, offering adequate shelter from the elements and predators, such as other birds of prey and domestic animals. The area below a nesting box will become dirty, so place it in a quiet area, ideally on the shaded side of a large tree or building, away from your main living areas.
Keep an eye on your owl nesting box – it is just as attractive to pigeons and bees. Avoid using toxic pest control chemicals in the box, however, as this is likely to deter owls from nesting. Also avoid using poisons in your garden, to kill rats for example, as they might also end up poisoning your owls.

When mounting your nesting box, make sure it is securely attached and is in a position that is most likely to attract owls.