and only raise a few young each year,
barn owls can begin breeding when
they are as young as 8 months, often
raise four to seven young in one brood,
and sometimes nest two or more times
in a year when prey are plentiful. While
late spring-early summer is the peak of
nesting activity, incubation and brood-rearing
can occur during any month of
the year in Illinois. One pair in Marion
County hatched five clutches and
fledged 15 young in a marathon of non-stop
nesting lasting 23 months. The flip
side of living fast is dying young, and
most barn owls don’t survive until their
second birthday in the wild. Fewer than
20 percent of adult barn owls will sur-vive
more than a single nesting season.
Besides a good supply of rodents
and secure nesting sites, barn owls
don’t need a lot to thrive. Barn owls are
not well-suited to cold temperatures,
and they are less effective hunting in
heavily wooded areas, so they are
found in a variety of open habitats in
tropical and temperate zones around
the world. The Illinois-Wisconsin state
line is roughly as far north as barn owls
can survive through the winter.
Barn owls are highly adaptable to
potential nest sites. True to their name,
barns, grain bins, silos, belfries, nest
boxes and a variety of other human
structures all may be used for nesting,
in addition to natural nest sites, such as
tree cavities and dens on cliffs and
bluffs. Because young owls often dis-perse
hundreds of miles in search of
their own mates and nesting areas after
leaving the nest, barn owls can readily
colonize areas far from other known
barn owl populations. Given their wide
distribution and tolerance of human
activity, and tendency to nest in barns
and other structures, barn owls are like-ly
the most familiar owl in the world.
In spite of this versatility, barn owls
are rare in the Midwest and endangered
in Illinois. Population declines since the
1920s are best correlated with chang-ing
agricultural practices, particularly
the shift from small-field diversified
farming practices, including perennial
grasslands for haying and grazing, to
large-field annual row cropping, which
reduced the abundance of small mam-mals
across large portions of the land-scape.
Voles—short-tailed, stocky balls
of brown fur about the size of a chick-en
egg—are the preferred prey of barn
owls in the Midwest, and are much
more abundant in hay, pasture, prairie
remnants, roadsides and other perenni-al
grasslands than in cropland.
From 1950 to 2007, the area devoted
to hay and pasture in Illinois decreased
by more than 5 million acres, whereas
corn and soybean acreage increased by
9 million acres. These land-use changes
correlate with the declining popula-tions
of many types of farmland
wildlife, including pheasants, quail, rab-bits
and many grassland-nesting birds.
The same types of land-use changes—
and downward barn owl population
trends—have been reported from
Europe. Barn owl conservation has
been widely attempted, with mixed
success. Nest boxes installed for barn
owls are readily adopted, and in some
areas have led to population increases
where adequate prey are available.
Releases of captive-reared barn owls,
on the other hand, have not produced
clear benefits to wild populations in
spite of being repeatedly attempted.
Although barn owls are rare in Illi-nois,
they remain broadly distributed.
Over the past 20 years (1990-2009),
barn owl nesting has been reported
from 31 counties, mostly in the south-ern
half of the state (see Figure 1).
Barn owl populations are secure in Mis-sissippi
River Valley states south of Illi-nois,
and populations in some Mid-western
states, including Missouri and
Ohio, appear to be expanding. In Illi-nois,
the establishment of about
800,000 acres of new grasslands
through the Conservation Reserve Pro-gram
beginning in the late 1980s prob-ably
created improved foraging habitat
for barn owls, and may be contributing
to the apparent increase in barn owl
reports since 1990. Counties in south-ern
and south-central Illinois, where
many of the recent barn owl nest
records are located, have large areas
enrolled in the Conservation Reserve
Program (see Figure 2).
Over the past few decades, Depart-ment
of Natural Resources biologists
and others have occasionally put up
barn owl nest boxes, most of which
have not been regularly monitored.
Many of the barn owl nests that are
reported are found under haphazard,
often unfortunate, situations, such as a
tree with a nest cavity being knocked
down by a storm, or a nest in an old
structure revealed during demolition.
With the support of a State Wildlife
Grant (T-35-P-1) from the U.S. Fish &
Wildlife Service, DNR and the Illinois
Endangered Species Protection Board
formed a team in 2009 to develop and
implement a recovery program so that
barn owls no longer need to be listed as
threatened or endangered in Illinois.
In 2010, the team solicited reports of
barn owls, searched databases and other
reports, revisited sites with past barn
owl nesting activity, and checked sever-al
nest boxes that had been in place for
years. The results were pleasantly sur-prising:
at least 19 barn owl nests in 16
counties (see Figure 1)—nearly as many
nests as reported through all of the past
decade. Many of the nest boxes which
had been put into place years earlier
were still in good condition. Other dam-aged
nest boxes were replaced, and 45
new nest boxes installed.
The Illinois barn owl recovery plan,
approved by DNR and the Endangered
Species Protection Board in November
What should I do if I find a barn owl nest or injured barn owl? It happens
every year: A thunderstorm knocks down a hollow part of a silver maple in some-one’s
yard, or an idled grain bin is being cleaned out, and suddenly young barn owls are
on the ground, scrambling for safety. Some are fully feathered, others are smaller and
much less developed. What to do? Resist the temptation to intervene, and only move
birds if they are in immediate danger, moving them only as far as is absolutely necessary.
Contact a DNR biologist to help resolve the situation (www.dnr.state.il.us/conserva
tion/naturalheritage/sstaff.htm); in addition to being endangered in Illinois, barn owls
are federally protected like other birds, and having them in possession without permits
is illegal. Only injured birds should be taken to a wildlife rehabilitator, as released birds
have lower survival than wild birds. Remaining in the care of their parents in the wild is
a young barn owl’s best chance for surviving. Young barn owls in a nest vary in age by
up to 2 weeks, so smaller, less developed birds are normal, and not a sign of disease or
malnourishment. Young barn owls can be placed into a nearby secure nest box, and
their parents will find them and resume caring and feeding for them. The adults may also
try re-nesting in the nest box.
June 2011 16 / OutdoorIllinois June 2011 OutdoorIllinois / 17
Barn owls feed at night on voles
and similar-sized prey.
In addition to natural cavities,
barn owls nest in barns, grain bins
and other human-structures.
Barn owl populations have
increased in some areas where
nest boxes have been installed.
Figure 1: Reported barn owl nesting Figure 2: CRP acreages relative to
reported barn owl nesting
(Photo by Dan Kirk.)
(Photo by Dan Kirk.)
(Photos by Terry Esker.)
