Tawny owl nest box

There are many factors to consider when choosing a bird of prey nestbox. Please read our advice carefully before purchasing.
Care must be taken when siting this nest box as tawny owls can be aggressive when they or their young are approached. It's best to leave them alone while they're nesting.

Installation and health and safety considerations

Owners must choose a suitable site (please see the following section) and then plan how to install the box safely. 
Given the varying locations and methods for installation, the RSPB does not provide detailed instructions for installing the box. 
Some general principles to consider for each location include:

• Take account of the weight and bulk – how are you going to get the box safely up to the place that you have chosen?
• How will it be fixed in place – do you need to do any preparation first?
• Do you need others to help – e.g. holding ladders, passing tools and equipment, keeping others away.
• Do you need any protective clothing – e.g. the person below holding the ladder may be advised to wear a helmet!

Where to site your tawny owl nest box

Tawny owls are typically woodland birds and nest boxes can be installed in both the countryside as well as towns and cities. Natural nest sites used by tawny owls include tree hollows, crows nests, squirrel dreys and sometimes holes in buildings. This ‘too-whit too-whoo’ owl is a versatile bird of prey feeding on a wide range of prey including small mammals, birds, insects and amphibians, and therefore can adapt to live in a variety of habitats.

Siting and installation tips

• Site box on a suitable mature tree within woodland or a copse or alternatively on a mature tree in hedgerow.
• The entrance should face East/NE/SE - away from the prevailing wind - this is not critical in dense woodland.
• Tawny owl chicks will leave the box at approx. 3-½ weeks of age, to branch into the upper tree canopy, where they will continue their development. Therefore it is important that there are branches close to the box entrance to assist the young in climbing up into the canopy.
• Ensure the front of the box is not obstructed and there is a clear flight path into the box.
• The height of the top fixing point should ideally be between 3 - 4m (10 -13 ft)
• Fix the box at the top and bottom fixing points using a suitable strong fixing. Ensure the fixing is tightened securely to avoid the box moving, but make allowance for the natural bend in the tree trunk and do not over-tighten against the bend, as this may result in damage to the box and/or fixing point. If necessary, brace the box using additional fixings to ensure that it is firmly fixed.
• Avoid siting the box above water-filled ditches, which may present a hazard to emerging chicks if they fall from the box.
• Avoid installation within close proximity to major roads or motorways, to minimise risk of low flying owls becoming traffic casualties.
• There is no need to add nest material to the box.
• It is not recommended that tawny owl boxes are installed close to areas of regular family activity, as tawny adults can be very protective in the breeding season and may attack humans and/or pets in defence of their young.
• Tawny owls are territorial so only one pair will occupy a woodland - however additional boxes can be installed to offer an additional roost or secondary nest site in the event that squirrels occupy a box or fill it with leaves.

Signs of Occupancy & Monitoring

Tawny owls are more discreet when using boxes than other species. Avoid climbing ladders to open the box - there are other clues to find out if they are at home:

• Look for wear on the front lip of the box entrance.
• Watch for owls flying to and from the box at nightfall or sat in box entrance (keep your distance).
• Chicks will also sit at the entrance and on the perch when first old enough to climb out of box.
• Check for pellets on the floor beneath the box.
• If the box is near your house, there will be a lot of noise near the box in the early spring, indicating the pair bonding between male and female.
• Tawny owls are early breeders, usually breeding just once in a year, with eggs being laid as early as February/March, although typically late April - May is the time most young are seen as they leave the nest and branch at just under a month old
• Owlets will often sit on the box perch when just a few weeks old.
• As eggs are laid and hatch a few days between each other, age of young owlets will vary.
• Grey squirrels will sometimes occupy tawny owl boxes and fill the box with leaves and twigs - (see below)

Maintenance and inspecting your tawny owl nest box

To avoid flushing an owl on eggs or with newly hatched young it is important that you follow these guidelines when considering any maintenance to your tawny owl nest box:

• Annual inspection is recommended to ensure box is clean and ready for the new season.
• Inspections should be carried out in the autumn (Sept - Dec) and it is best to do this work an hour before dark, so that if an owl is flushed from the box, it will have minimal time in daylight, where it may have to endure mobbing from other birds.
• If essential maintenance has to be carried out between January and May, watch the box over a period of days at dusk through to nightfall to see if any owls are visiting it - this could indicate it is being used as a nest site
• It is best to inspect boxes an hour before dark and during dry calm weather to avoid flushing a bird into the perils of rainy or windy weather. If there are visible signs that an owl is in the box, monitor it from a distance at dusk as it may not be appropriate to disturb the bird.
• Boxes that have been inhabited by grey squirrels or birds may be filled with twigs or leaves - this should be cleared out (ensure that any birds’ nests are not in use).
• It is advisable to wear a dust mask and heavy duty gardening type gloves when clearing out boxes.
• Any bird or squirrel disturbed in a box will probably exit rapidly - be aware of the risks of this when at the top of a ladder.
• RSPB boxes are treated with an eco-friendly water based preservative where required - if re-coating ensure that the preservative is also an environmentally friendly water-based product.
• Tawny owl chicks that have branched out of the nest box, sometime fall from the safety of the trees. This puts them at risk of being attacked by ground predators. If you find a chick on the ground, the parents will be very close by, so the chick should be put into the nearest tree, where it will be able to climb back up to safety. Do not take the chick in and feed it, as the chicks ‘imprint’ very easily, and a tame chick cannot be released and will have to spend a lifetime in captivity.