How to build the best nest box for a tawny owl

The best nest box for a tawny owl

Each year tawny owls nest in my garden in boxes built especially for them and over the years I’ve learned what sort of box suits the species best and where to site it. I am often asked how to build a nest box to attract tawny owls and so I hope this post will help answer most questions.

Where to site your tawny owl nest box

Before you set about building a nest box, you need to think about where it is going to go. Attracting a tawny owl into a nest box depends on a few factors: the availability of natural nest sites in your area and the available habitat and prey. Tawny owls live in wooded or partially wooded areas; you even get them in large gardens and parks in towns and cities and consequently their nest boxes need to be sited in a coppice or wood in a deciduous tree. People often make the mistake of putting owl boxes up where they can get a good view of the owls. But that is the last thing an owl wants.

To ensure breeding success, tawny owls also need to feel safe. They are much more susceptible to disturbance around their nest site than barn owls.

Choose a site close to a tawny owl’s natural hunting ground

Unlike barn owls, which are niche feeders and need to be close to rough grasslands where they hunt for small rodents, tawny owls feed on a wide variety of prey and will take anything from small rodents to rabbits so your options when it comes to choosing a site for a box are wider. It is always a good idea to put up a box if you know you already have tawny owls in the area. Listen out for their calls at night and look for their white droppings for clues.

Face your nest box away from wind and harsh sun

Their nests should be out of prevailing winds, so face yours southeast. It needs to be at least three metres off the ground with branches nearby for fledgling chicks. These youngsters explore the world outside their nests by hopping along the branches long before they can fly. This behaviour is known as ‘branching’.

Ideally, a tawny owl box also needs to out of the full sun, although most of the year this isn’t too much of a worry since tawny chicks have often fledged before the weather gets too warm. And the box needs to be sheltered to avoid being exposed to heavy rain.

What size should a tawny owl nest box be

I’ve noticed that designs of commercial tawny owl boxes, or boxes suggested by charities, offer too small a nesting space. These are usually just 25cm square at the base. I recommend a base that is at least 30x 35cm.

Tawny Owls Prefer Small Boxes

Although tawny owls prefer a smaller nesting cavity than barn owls, the spaces inside most boxes on the market are usually too small for the male and female to sit together in early spring for their courtship and later egg-laying. Often there is also not enough space for the adults to feed their chicks. And I’ve noticed the lack of space means they often land too forcefully onto their eggs or chicks – sometimes damaging their tails in the process. There also isn’t enough space in there for fledgling owls to flap their wings. This is important for them when it is time to climb out.

Be Aware of Spring Showers When Siting your Tawny Owl Box

There are some tube-shaped boxes on the market. These open at the top and are designed to be strapped under a leaning branch. But these also present problems for tawny owls since they are such early nesters the open top means they get drenched by heavy spring showers and young chicks can perish. Also, if they get too wet, the bottoms of these boxes don’t last and often rot.

 

Tawny owls don’t always use the nest box you offer them

Even though these commercial boxes are designed with tawny owls in mind, I have found that the birds don’t always go into their designated boxes. In my garden the owls often choose to nest in boxes designed for kestrels, but here the problem is that their chicks fledge too early as this box-design is easy for them to get out of.

Tawny owl boxes should be tall

It is important that a tawny owl nest box is tall, so that the chicks cannot climb out before they are ready to fledge. I make mine at least 80cms high. Tawny owl chicks are notoriously adventurous and you often have accidents. Once I ended up drying two tawny owl chicks with a hairdryer after they got caught in a downpour and were unable to fly back to safety.

My best tawny owl nest box design

I have designed my own tawny owl boxes. My boxes have a base that is at least 30x 35cm and are about 80cm high. This gives the owl family room as they grow. I like to use old tree stumps for my nest boxes. These offer the owls a natural hole to nest in and gives me an attractive prop for my paintings and photographs.

Line your tawny owl nest box with wood chippings

I recommend putting two inches of wood chippings into the bottom of a tawny nest box. Tawny owls do not collect nesting material. They make a nest scrape in the debris that they find at the bottom.

Watch out for pests invading your nest box

Other species, such as jackdaws and grey squirrels often colonise owl nest boxes and this can be a real problem as it deters the owls you are trying to attract. Watch the clip below to see this squirrel determined to nest in an owl’s box!

There is no simple solution to this problem; you just have to clear out the nest box of the bits of twigs that the jackdaws and squirrels put in each year. That is until you get a resident owl, at which point the owl will chase these intruders away itself – hopefully! This can be tedious, but it is worth the effort for the bright winter’s night when you walk out into the garden and hear the comforting ocarina call of a courting tawny owl!

My tawny owl nests are wired with cameras and microphones

I fit cameras and microphones inside my owl boxes so that I can follow the intimate lives of these owls from screens in my studio and gallery. You can also see the best footage I get on my Tawny Owl Cam which follows the owls throughout the breeding year.

 

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Tawny Owl Paintings

The following paintings are portraits of the tawny owls that have lived in my garden over the years and form part of  my collection of owl art prints.