Box clever and you could help revival of a rare bird
I HAVE had two enquiries about installing nest boxes for barn owls recently, and there are a couple of readers with large outbuildings hammering away as I write, intent on attracting the ghostly white beauties to their countryside homes. The time is nigh if anyone else is thinking along the same lines.
As barn owls’ nestboxes need to be ‘justright’, I have been in touch with the real experts at the Barn Owl Trust. But first, a little history. Fossil records indicate the Barn Owl appeared on earth approximately two million years ago, which is long before modern man appeared, and their fossil bones have been found at Earl Sterndale and Creswell Crags.
At Cresswell, a gorge honeycombed with caves and smaller fissures near Bakewell, stone tools and remains of animals, including the ancient regurgitated pellets of barn owls, were discovered in the caves by archaeologists, providing fascinating evidence of life during the last ice age.
The barn owl was feared by ancient Europeans and revered by Native Americans, and few birds have such a supernatural reputation - one fuelled by the bird’s ghostly white appearance, silent flight and intermittent screech.
The UK population has declined by over 70 per cent in 50 years and, to a large extent, only stabilised by the provision and maintenance of nest-boxes.
Nest and roost sites have been lost through a wide variety of causes, including the general deterioration of traditional farm buildings, unsympathetic barn conversions, loss of hollow trees due to Dutch Elm disease, and the general ‘tidying up’ of the countryside.
Church towers are usually netted-off to prevent access by birds and modern farm buildings are generally unsuitable unless a nest-box is provided.
Barn owls prefer open habitat and usually hunt by flying slowly back and forth (quartering), about 3m above the ground, looking and listening for their prey.
If suitable perches such as fence posts are available, the owls may save energy by hunting from these. Its diet consists mainly of small mammals, particularly field voles, common shrews and wood mice. Prey is often swallowed whole and the indigestible parts, the bones and fur, regurgitated as a pellet.
Barn owl habitat includes rough grassland, field margins, hedgerows, woodland edge, stubble fields, drainage ditches and farmyards.
Within their home range a pair of the owls may have one breeding site, one or two roosting sites and perhaps a few sites which they only visit, or roost in occasionally.
May is the time when most eggs are laid, normally in a dark cavity or on a ledge in an old building or hollow tree. Normally between four and seven eggs are laid over an 8 to 21 day period.
It is not surprising that some readers would like to have a barn owl nesting in their grounds, and this is to be encouraged, especially as the circulation area of this column has the least barn owls in the UK. However, strict guidelines need to be followed.
Your property should be at least 1km, and preferably more, from the nearest motorway or dual carriageway, because these roads account for a great number of barn owl deaths each year.
If you have a large building that a barn owl can enter at, say, at least three metres above the ground, then this is almost certainly the best place to put a nest-box.
Boxes in buildings are easier to erect, cheaper to obtain and last a lot longer. The extra shelter afforded by the building will benefit the owls.
If there’s a building with no access, a small hole can be made relatively easily. And remember, it’s the ‘hole’ the owl is after, and this needs to be visible from the access point.
Buildings that are in human or agricultural use are usually suitable, as barn owls can get used to almost any kind of activity as long as they can stay out of sight.
A tree box is a next-best option. Tree boxes are more expensive and more difficult to erect. They don’t last as long, and the owls won’t have much shelter. But, hey, any port in a storm for this local rarity.
As always, let me know how you get on. If you don’t own a mansion, a farm, or a woodland, you can join a local barn owl group. Check out www.pebog. org.uk/barn-owlinformation »