1.)
Construction:
The important elements of a barn owl nest box are roominess (to
accommodate the species' large broods) and seclusion from predation.
Although barn owls have used oddest of designs, the style shown here
has proven successful when placed in a variety of situations. If
placed up beneath the barn's roof, there is no need to put a roof on
the box. If placed lower in the barn or in an open-topped silo or
tree, a roof must be installed to provide the necessary seclusion
and protection from weather.
Construction
is simple. The sides are first fastened to the front and back and
then the bottom is attached. If a top is used, it should be put on
after the box is installed to facilitate easier nailing. Use
exterior plywood if the box is to be placed in an exposed situation.
Approximately nine drain holes, 1/4-1/2 inch in diameter, should be
spaced throughout the bottom. Cover the bottom with one or two
inches of wood shavings, as barn owls place no nest material.
2.)
Installation: Barn owls prefer to nest in buildings, and
boxes should be installed high to lessen human disturbance and the
dangers of predation from snakes, raccoons and cats. If placed in a
barn, the front should face into the barn. The back can be nailed
flat to the barn. Usually, a brace or stud can be located on which
to secure the box firmly along one side. Metal straps attached on
the back can be bent to hang the box (drawing below) in a barn or
inside a silo. In some regions, barn owls use boxes that are simply
wired in place high in a large tree.
The
most productive site for a barn owl box is where individuals have
been seen. Due to the species' rarity, the possibility of attracting
them in other areas is remote but worth a try. The best localities
are rural. Areas where there are open grasslands and crop fields and
where grain spillage results in high mouse populations are
especially suitable for nesting barn owls.
3.)
Biology: Barn owls are permanent residents and may nest
at any season. Their clutch of five to ten white eggs will produce a
varying number of the young, depending on availability of prey.
Incubation requires three weeks. The young, who vary in size due to
their hatching dates, fly at about seven weeks of age. Barn owls
often nest in the same site repeatedly.
Barn
owls are considered to be our most beneficial owl, owing to their
appetite for animal pests. One once was observed delivering 16 mice,
three gophers, a rat and a squirrel to a nest within 25 minutes. A
rare species in Missouri, the barn owl is found worldwide, nesting
almost totally in buildings in the Old World and in hollow trees and
burrows in much of the western United States. In Missouri, they
utilize a variety of sites. Throughout
much of its range, the barn owl's numbers are thought to be limited
by the availability of suitable nest sites.
4.)
Comment: Should the beautiful, barn owl accept your box,
you will be among the fortunate few. You should reduce human
activity near the site and discontinue the use of rodent poisons. |