Barn Owl nestbox
'Nest' is not really the appropriate word to use in relation to Barn Owls, since they build no nest as such, but lay their eggs on a layer of pellets which has accumulated in their roosting site. Such sites are deep spacious cavities in trees (especially Elms), dark corners of barns, churches (see: Churchyard Conservation), and old buildings, or even gaps in straw stacks. With the loss of so many elms in recent years through disease, and so many old buildings through modernisation, nestboxes provide a real opportunity for this declining species to re-establish its population.
Owls may accept a nestbox readily, but use it only for roosting for as long as two years before finally breeding. There is no real design for a Barn Owl nestbox - any large box is acceptable if it is at least 18 x 18 x 24 inches. For internal use (barns and old buildings) the traditional tea chest can be ideally adapted; but for external use, good quality, heavy, waterproof board must be used.
The ideal site for a box is a dark corner on a beam in an undisturbed building near farmland, away from busy roads, and where there is permanent access for the owls through doors, windows or other such holes.
An entrance hole 9 x 9 inches should be cut from one of the bottom corners, and a lipped tray fitted in front of the entrance to provide an exercise area for the young owls.
It is also possible to site boxes in modern, prefabricated farm buildings, using battens, bolts and wire, but the need for a permanent means of access to the building for the owls is vital.
