‘Boxing for Barn Owls’ is how Major Nigel Lewis sometimes phrases it. He’s designed many versions of nestboxes for Barn Owl over the years, as Nigel and his team worked their way across Wiltshire to conserve the white owl.
“The #7 design is doing well,” Nigel told me last week, “the Jackdaws can fill the entrance but not the box.” His mark seven is a heavyweight house, made with 18mm-thick marine plywood, intended to last for decades! This is his 7th generation of box design, evolved from the times when Nigel adapted old army ammunition boxes as Barn Owl boxes.
The Lambourn Valley Barn Owl Group and volunteers at Sheepdrove Organic Farm have been developing my prototype for a small Barn Owl nestbox this spring. After carefully considering the plus-points of various designs, I came up with an outdoor nestbox which is easier to make and install than most I’ve tried.
A smaller box is useful for 3 main reasons:
- Heavy and bulky boxes are difficult to install. Lightweight boxing is easier!
- The cost of large nest boxes can be inhibitive to Barn Owl conservation groups.
- More nestboxes are useful and obviously a small box uses less plywood than a bigger box – so you can build more!
Being able to provide additional alternative roost and nest sites can be very important – for example:
- Barn Owl males often require a roost apart from the breeding site once the eggs hatch;
- owlets seeking their own home need somewhere to go;
- during winter owls might stop defending the breeding site, so an alternative roost is valuable;
- competition for nesting cavities can be very high.
Key factors considered in my design are the weather, competitors such as Jackdaw, and the behavioural needs of Barn Owl – especially at breeding time.
Because my box has a low extrance, a baffle is vital to keep chicks inside until they are large and agile enough to climb. The baffle shelters the ‘main chamber’ which is large enough to fit a family of young chicks. Although it might not be roomy enough for a lot of fully-grown owlets, after about 4 or 5 weeks of age the eldest will be able to move into the hallway. They want to be first in line for food deliveries! Owlets are eager to explore perches as soon as they are able to, getting out and about, and flapping their wings.
This triangular owl box has the naturally rain-shedding shape of the larger A-shape designs promoted by Iain R Taylor (1994, Barn Owls) and Colin Shawyer and Sue Dewar (1996, Boxes Baskets and Platforms).
Have I been able to understand the needs of the owls? Will this small, lightweight owl box design be a success? We just have to wait and see…