BARN OWL NESTING BOXES
The preferred “natural” nest sites of Barn Owls include
hollows in high trees, tall rural buildings (old and new),
rock crevices & holes in cliffs and though Barn Owls
like their privacy, successful boxes can be sited near to
quite busy locations such as farmyards. ln all cases,
however, the predominant requirement is shelter from rain,
due largely to the Barn Owl’s lightly oiled plumage, which
makes them more prone to soaking than other species.
So even when contemplating an indoor box - best when there
is little risk of immediate disturbance and a permanent
& visible means of access (Barn Owls look for holes,
not boxes) - the idea is to create a cavity space that is
enclosed on at least three sides and has at least one
internal baffle to allow the inhabitants to hide away from
view.
An important design element of Barn Owl nestboxes is the
provision of a front shelf or tray, which will allow
fledglings to exercise their wings before first flight -
Barn Owl chicks take a long time to fledge (about 8 weeks
on average) and, once fledged, remain dependent on their
parents for a further three to five weeks.
The ideal size of the Barn Owl box is large - a minimum of
15” x 13” x 25” is recommended, with 6” ledge and 8” x 6”
entrance (36 x 32 x 60cms with 15cms ledge & 19 x 15cms
entrance). A removable lid or panel should be included for
qualified inspection and occasional clearing out between
occupants. A converted tea-chest also makes an ideal indoor
nesting box for a Barn Owl.
An indoor box should be securely nailed to beams, ensuring
that no nails, screws or other sharp edges or points are
left to protrude into the box or any part on which the
birds might perch. It should be positioned as high as
possible - at least 10 feet (3m) above ground level, but in
the case of unventilated modern farm buildings, below the
apex of the roof, where it can get very hot in summertime.
It is best to have the front opening of the box directly
facing the owl’s point of access to the building.
Alternatively Barn Owl boxes can be fixed under the eaves
of remote buildings and are likely to be as equally as
successful if they provide privacy, shelter from the rain,
direct access and are spacious enough.
Exterior Barn Owl boxes are best positioned in trees well
out of reach of the casually curious, (but not so high that
any stray owlet might be killed in the fall to earth)
either at the edge of woodland overlooking open land, or in
large isolated trees or on purpose-built poles located on
open meadow or grassland at a location at least half-a-mile
(1km) from the nearest busy road. The box needs to be sited
in or close to habitat that has an abundance of suitable
prey - small mammals, etc. Visibility from the nest and a
clear flight path to it are essential. Equally important,
the box needs to face away from the prevailing wind &
rain direction, usually towards the south east.
Tree-sited nestboxes are more likely to be used by other
species than those in buildings. The box should be firmly
and securely fixed to its support. Fixing a box to a tree
with nylon cable ties or bolts is certainly the most
conservationally correct. If possible, the box should be
angled so that the floor slopes slightly away from the
entrance, so that eggs remain dry & protected.
Further reading about the building & siting of
nestboxes can be found in a comprehensive booklet, Boxes
Baskets & Platforms, available price £8.99 + P&P
from The Suffolk Owl Sanctuary on 01449
711425
For
detailed plans to build your own Barn Owl box or a price
list for ready-made boxes,
please call us on 01449 711425