Tawny owls are nocturnal birds of prey that are found throughout Europe, parts of Asia, and the Middle East. They nest in tree holes, old squirrel dreys or artificial nest boxes put up especially for them. If you want to attract tawny owls to your property, putting up an owl nest box is a great way to do so. But what exactly should you put inside a tawny owl nest box?
Nesting Material
The most important thing to put in a tawny owl nest box is nesting material. Tawny owls do not build elaborate stick nests like many other bird species. However, they do like to have a base of nesting material to lay their eggs on.
Good nesting materials to use include:
- Wood shavings
- Sawdust
- Leaf litter
- Bark chips
- Dry grass
- Hay
- Pine needles
- Dead leaves
Aim to put in enough nesting material to cover the floor of the box to a depth of 2-3 inches. Do not use materials that could absorb moisture or get soggy when wet.
Key Properties of Good Nesting Material
The ideal nesting material for a tawny owl box should:
- Be non-flammable
- Be non-toxic
- Not get moldy if it gets wet
- Provide insulation
- Allow drainage
By using dry, non-biodegradable materials like wood shavings, sawdust or bark chips, you can create a comfortable, well-draining base for the owls to lay their eggs on.
Perches
It can also be helpful to install a wooden perch or two inside the nest box. Tawny owls like to perch on branches and tree limbs, so having perches gives them a place to sit inside the box.
Use natural tree branches or you can install wooden dowels. Place the perches diagonally from corner to corner across the box. Make sure to securely fasten the perches to the walls of the box.
Position of Perches
Consider placing the perches at different heights – for example:
- A higher perch near the entrance
- A lower perch further back in the box
This allows the adult owls to perch up high to guard the entrance, while the lower perch gives the young owlets a place to sit once they start moving around.
Bedding Material
In addition to nesting material on the floor, you can add bedding material that the baby owls can nestle into. Make sure any bedding you add is soft, insulating and won’t accidentally entangle the owlets.
Good bedding options include:
- Wood wool
- Shredded paper
- Straw
- Pet fur
- Natural wool
- Cotton batting
Place a 2-3 inch layer of bedding material on top of the nesting material. The female owl will create a nest bowl in the bedding when she is ready to lay her eggs.
Removing Old Bedding
Be sure to remove and replace the old bedding material each year. This helps prevent the spread of parasites.
Dispose of used bedding well away from the nest box to prevent any diseases or pests from lingering around the nesting site.
Protection from the Elements
Since tawny owls nest in tree cavities in the wild, their nest boxes should provide protection from the external environment.
Make sure the nest box:
- Is weatherproof and water tight
- Has a roof with sufficient overhang
- Has drainage holes in the bottom to prevent flooding
- Is insulated or has thick wooden walls to maintain interior temperature
You can also line the roof with non-toxic asphalt roofing felt to prevent leaks.
Blocking the Entrance
To give the owls more protection from the cold and wind, you can block part or all of the nest box entrance hole with a piece of bark or wood. The parents can get in and out, but this helps hold in heat when the female is incubating eggs.
Just make sure not to block the entrance entirely once the owlets start to approach fledging so they can look out.
Cleanliness
Keeping the nest box clean is very important for nesting success. Be sure to:
- Remove old nesting material, droppings and pellets after each nesting season
- Clean the box with a mild disinfectant and warm water
- Allow the box to air out and dry fully before putting in fresh nesting material
Wear gloves when cleaning and never touch baby birds if they are present. A box left uncleaned can allow parasites and diseases to accumulate from one year to the next.
Predator Protection
To prevent predators like martens from entering the box, you can add metal mesh screens or guards below and/or inside the entrance hole.
Avoid using chemical pest repellents inside the box, as the fumes may be harmful to the owls.
Nesting Timeline
When you provide nesting materials in a tawny owl box depends on when the owls in your area begin nesting. Here is a general timeline:
Time of Year | Nest Box Preparation |
---|---|
Late winter | Clean out old nesting material and sanitize box. Add fresh nesting material and bedding. |
Early spring | Ensure box remains clean. Monitor for owls checking out the box as potential nest sites. |
Mid-late spring | Female begins laying eggs and nesting. Male brings food to female in box. |
Early summer | Eggs hatch and owlets are brooded in nest. Parents deliver food to box frequently. |
Mid-late summer | Owlets fledge and leave nest. Parents continue to care for them. |
Early fall | Monitor box to ensure owlets have fully dispersed before cleaning out old nesting material after nesting season ends. |
The exact timing will vary based on your location and the pair of owls using your box. But this gives a general idea of when nesting activity occurs in tawny owls.
Maintenance
To keep your tawny owl nest box in good condition:
- Check the box after stormy or windy weather for any damage
- Watch for signs of rotting wood and replace boxes every 5-10 years
- Refresh protective finishes and re-waterproof the box when needed
- Ensure the roof is clear of debris so rain can run off
- Trim back any branches or vegetation that may overgrow the box
Providing a clean, dry and safe nesting environment will go a long way towards getting your box used successfully season after season.
Monitoring Use
Keep track of whether your nest box gets used each year. Look for signs like:
- Feathers around the entrance hole
- Molted feathers within the box
- Droppings at the bottom
- Pellets and leftover prey remains
This will let you know whether it is worth continuing to maintain the box in subsequent years. If the box goes unused for several years in a row, try relocating it or making adjustments to increase its appeal.
Conclusion
Providing an appropriate nest box with suitable nesting materials is key to attracting breeding tawny owls. Make sure to include:
- A base layer of nesting material such as wood shavings
- Perches for the adults to roost on
- Soft, insulating bedding for the owlets
- Protection from weather and predators
- Regular cleaning and maintenance
Follow this tawny owl nest box guide, and you are likely to have owls eagerly move into your box and raise their young! Just be sure not to disturb the box during critical nesting times.