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Barn Owl
Tyto alba [American Barn Owl]
[Published in 1938:
Smithsonian Institution United States National Museum Bulletin 170
(Part 2): 140-153]
The North American form of this world-wide species is widely
distributed throughout the warmer portions of the United States;
it is rare in the northern tier of States, north of latitude 41o,
but it increases in abundance southward and is especially abundant
in southern California. It is widely known locally as the
"monkey-faced owl" and has also been called "white
owl", and "golden owl," the last a pretty and
appropriate name.
Owls have always been victims of ignorance and superstition,
believed to be birds of ill omen and harbingers of misfortune and
death; and the barn owl, in particular, has been responsible for
many reports of haunted houses. But, in spite of its sinister
appearance and its ghostlike habits, this curious owl is one of
our best feathered friends, most worthy of encouragement and
protection, as a most efficient living mousetrap.
Nesting.--As I have had very
little experience with the barn owl, I quote the following
comprehensive statement by Bendire (1892):
Their nesting sites are quite variable and include all sorts
of places, such as natural hollows in trees, holes and cavities in
clay banks or cliffs, burrows under ground enlarged to suit their
needs, in the sides of old wells, abandoned mining shafts,
dovecots, barns, church steeples, etc., and sometimes, though
rarely, in perfectly exposed and unprotected situations, such as
the flat roof of an occupied dwelling-house in the midst of a
village.
Mr. W. O. Emerson, of Haywards, California, writes to me:
"A pair of Barn Owls nested the past season (1889) on the
bare tin roof running around a cupola of a neighbor's house, which
was surrounded by a low railing. Not less than twenty-four eggs
were laid and none of them were taken away at any time. There was
no nesting material on which the eggs were placed, not even a
single twig, and they naturally rolled around on the roof, as it
was impossible for the bird to cover them all. When taken down
finally and examined, it was found they were all rotten, caused,
no doubt, by the intense heat from the sun's reflection on the tin
roof."
Writing of his experience with the barn owl in Arizona, Major
Bendire (1892) says: "In this vicinity I believe they nest
mostly in deserted burrows of badgers, at any rate more than once
I saw them sitting in the mouth of such burrows."
The only nest of a barn owl that I have ever examined was shown
to me by E. Lowell Sumner, Jr., near Claremont, Calif., on
February 28, 1929. It as in a large, horizontal, natural cavity,
about 12 feet from the ground, in a thick, gnarled branch of a
low-spreading live oak; the owl flew out, as I climbed to the
nest, and did not appear again; the cavity was so deep that I
could barely reach the eight eggs that lay at the farther end on a
bed of rotten chips, rubbish, and bits of down. The nest had been
occupied on previous occasions.
As far as I can learn, from the experiences of others, the barn
owl shows a decided preference, in
California at least and apparently in Texas also, for nesting in
cavities, holes, or burrows, in cliffs or steep banks, which are
easily found or made in the numerous barancas or gullies to be
found in that region. Dr. B. W. Evermann (1882) says:
The site selected for the nest is most usually a hole or
crack in the wall of a baranca or cliff. During the past season, I
examined more than thirty nests, at least five-sixths of which
were thus located. The entrance to these holes, if in barancas, is
usually eight to ten feet from the surface of the ground; if in
cliffs, any suitable place on the face is selected. The cavity
usually extends inward nearly horizontally for a foot or more,
then bends down slightly, continuing at that angle for two or
three feet, slightly widening to the end where it is quite
commodious, being often as much as two feet in diameter. For some
time it was a perplexing question to me as to how and by what
these holes were excavated. After careful investigation, I am
convinced that the owls themselves make many of them. A slight
crevice or squirrel hole is selected, and, with their powerful
claws, they hollow it out to proper dimensions. Both birds are
frequently found occupying the cavity during the day--the male to
one side of the nest. . . .
We visited a deep baranca a few miles east of Santa Paula,
where we knew them to be abundant. . . . We dug down to eleven
nests altogether, from six of which we got fourty-four eggs,
ranging from six to ten eggs to the nest.
But the burrows are not always selected. Two nests were
found in holes in oak trees, one was found in a barn. . .and in
April, 1880, I found a pair occupying the deserted nest of a crow,
which was placed about twenty feet from the ground in a
cottonwood. I visited this nest at two different times before
taking the eggs (five in number), and drove the female from the
nest on each occasion. The use of a nest of this kind by the Barn
Owl is very rare, I think; careful search failed to discover a
second instance of this kind. . . .
As to whether it constructs any nest seems to depend
entirely where it nests; if in holes in cliffs, trees, or walls,
no lining is used; if in barns or houses, it constructs a rude
nest of sticks or other rubbish easily brought together.
Julian K. Potter and John A. Gillespie (1925) made some
extensive studies of the home life of a pair of barn owls near
Gloucester, N.J. The nesting site was an old tower, "a frame
building of three stories shaped like a truncated pyramid, with a
water tank at the top. It was in an extremely dilapidated state of
repair, and the window panes were entirely missing." The nest
was in a "hole in the floor just in front of the stairway
leading to the roof and about three feet from the open window. . .
. The nest cavity was approximately twenty inches deep, fifteen
inches wide and eight inches high, the sides being formed by
vertical floor beams, and the top and bottom by the floor and the
ceiling of the room below. . . . No nesting material of any
description was in evidence except a small clump of black feathers
which possibly once belonged to a Starling."
Ivan R. Tomkins writes to me that "a nest of the barn owl
was found in one of the steel range lights on the Savannah River,
March 30, 1929, with five eggs. The nest was in a steel box about
2 feet square, with part of the west side open to the sun, under
the light, and was liberally carpeted with pellets. The keeper of
the light says the owl has nested there for about four
years."
A. B. Howell (1912), referring to the Todos Santos Islands,
writes: "April 16 I found a nest in a deep cleft in the
rocks, twenty feet above the sea, which contained a single
nestling two-thirds grown. This side was newly occupied, but on a
ledge four feet above the floor of a cave on the higher ground was
a nest that must have been used for generations. Beneath it was a
pile of refuse and pellets two or three feet high."
W. E. D. Scott (1892) reports "a pair breeding on the hull
of an abandoned dredge that had belonged to the company engaged in
draining and reclaiming land in the vicinity of Lake
Okeechobee."
Eggs.--Major Bendire (1892) says:
"The average number of eggs laid by this species is from five
to seven, seldom less. Larger sets containing from nine to eleven
eggs are by no means uncommon; it is questionable, however, if
every egg in such large sets is usually hatched.
"In shape the eggs are mostly ovate, a few are elliptical
ovate, and a single specimen before me is elongate ovate. They are
pure dead white in color, the shell is finely granulated, and they
are decidedly more pointed than Owls' eggs in general."
The measurements of 59 eggs average 43.1 by 33 millimeters; the
eggs showing the four extremes measure 48.8 by 32.5, 43.5
by 35, 39.8 by 33.3, and 40.5 by 27.5
millimeters.
Young.--The eggs are laid at
intervals of two or three days, and incubation
begins soon after the first egg is laid; consequently the young
hatch at similar intervals and vary greatly in size. The period of
incubation is said to be from 21 to 24 days. Bendire (1892) says
that "both sexes assist in incubation, and the pair may be
sometimes found sitting side by side, each with a portion of the
eggs under them."
E. L. Sumner, Jr. (1929) has made some intensive studies of
young barn owls. On March 4, 1928, he found that three of a set of
eight eggs had hatched, and says in his notes: "All three
whimper continually, in feeble tones. The oldest is able to stand
up, although weakly and with nodding head." On March 10, only
two eggs remained unhatched. On the 17th, the oldest "hisses
harshly when handled, but is till quite docile. It stands up and
walks about with ease." March 26: "The youngsters are
quite lively, even the smallest. When set down in the long grass
they stand up to their fullest height and crane their necks in
search of a hiding place. As yet, all the birds can be handled
without danger. When disturbed, a and b (the oldest two) hiss
harshly and sway from side to side with heads lowered and extended
wings inverted, after the manner of owls. If further provoked they
throw themselves on their backs and strike out with both
feet." April 16: "Youngsters more active and
aggressive than ever. When placed on the ground they strike at
each other, as well as at any other object that comes within
range, and at times they even assume the offensive, running toward
me with open beaks and upraised, inverted wings."
From that time on, the young became more pugnacious, until, on
April 27, he called the "actions of young positively
unprintable"; and on the 6th of May, he had to tie them down
to keep them from flying away. On May 27, the youngest bird left
the nest. An interesting discovery was that, when between six and
seven weeks old, every one of the birds began to lose weight,
though before that they had exceeded the average weight of adults.
Messrs. Potter and Gillespie (1925) made several visits to the
barn owl's nest in the old tower, referred to above. On their
second visit, on May 13, 1924, the nest contained seven young,
three days to two weeks old. The youngest "was a pitiful,
bedraggled and filthy little fellow, having evidently been
trampled on by the others. In size he was little larger than a
baby chick, and at times he uttered a faint tremulous whine. The
rest were of assorted sizes, the largest about the size of a
Pigeon. Dark colored pin feathers were in evidence in the wings of
the two largest. . . . The cavity was inspected and was found to
be in an exceedingly filthy condition--the floor covered with a
layer of casts powdered into a furry mass by the feet of the
young. Yet in such unsanitary surroundings the fledglings with the
exception of the smallest, were clean, except their feet, which
were quite filthy."
On June 9, "dusk was falling, but it is still light at
eight p.m. when one of the young ones made the initial call for
food. This is a rasping sucking noise, and can readily be imitated
by drawing in the breath sharply through the corner of the mouth,
and keeping the teeth closed. This is, no doubt, the 'snoring'
call described by Dresser (Knowlton, 'Birds of the World,' page
516). It might also be likened to the sound made by an
ill-mannered person eating soup! It actually sounds as if the
bird's mouth were watering in anticipation of food, and it kept
sucking back the saliva. The others soon joined in the call, which
by eight-fifteen was very insistent."
At 9:00 p.m., "adult Owl drops on window-sill and then to
floor as before. We flash light on her. She stands at entrance to
nest peering down. Either a pine or a short-tailed field mouse
hangs from her bill by the back of its neck. She appears to be
waiting for the young to take the mouse, but they are raising a
great racket under the floor, apparently afraid of the light. The
adult bird disappears into the cavity, feeds the young and
reappears. The light seems to daze her as she looks toward us with
black, blinking eyes. . . . Suddenly she jumps and flies directly
toward us, lighting on the stairs about seven feet from where we
sit. . . . Then she seems to spy the window and silently glides
out into the night."
Another, similar feeding was observed at 9:18. Summing up their
observations, the say: "Both adults participated in the
feeding. Female an 'earlier riser,' her earliest visit made at
8:20 p.m. while male put in his initial appearance at 9:45 p.m.
Under normal conditions the feedings no doubt continue throughout
the night, but during our observation the adults were frightened
and paid fewer visits. Feedings were in the ratio of two by the
female to one by the male. The first evening the bringing of food
was witnessed, the female, obviously suspicious of our presence
but not alarmed, brought three mice within a period of fifty-three
minutes."
They learned by subsequent observations that the young owls
were ready to leave the nest and fly out into the world
"seven and one-half to eight weeks subsequent to
hatching." And they inferred, from the sounds heard and the
behavior of the adults, that the young lived in the surrounding
trees and were fed by their parents for some time after leaving
the nest. They describe the following calls of the young:
(1) A high-pitched quavering whine uttered by recently
hatched fledgling before eyes were open.
(2) A loud hiss uttered through the open mouth, expressing
alarm. As the fledglings develop in size this hiss gradually
changes into a throaty, hissing scream devoid of tone, which
presumably later becomes the adult "scream."
(3) A short rasping call, or "snore" (Dresser).
This is the food call and varies considerably in pitch.
(4) A discordant scream, similar to that of the adult, but
of shorter duration and higher pitch. Uttered on the wing at age
of approximately 10 1/2 weeks.
A young bird handled by Howard H. Cleaves (1910) uttered
"a plaintive chi-le-le-le, chi-le-le-le, chi-le-le-le,
repeated very rapidly."
Plumages.--The young barn owl is
easily recognized at any age by its much prolonged and pointed
face, exceeding all other owls in this respect. It also differs
from other owls in its sequence of downs, having at first a fuzzy,
white down, which is followed by a woolly, buffy-white down; it
never acquires a long, fluffy, soft, juvenal plumage, so
characteristic of other young owls; this is probably due to the
fact that the first winter plumage is acquired at a very early age
and is nearly complete when the bird leaves the nest. E. Lowell
Sumner, Jr. (1933) has described this very well as follows:
The fuzzy white nestling down is the only covering of the
young barn owl until about the sixth day. At this time the
buff-colored second downy plumage begins to appear, and carries
the earlier down away on its tips. This second down rapidly
develops into the thick, woolly covering which is so
characteristic of young barn owls, and remains as a conspicuous
feature until the bird is about fifty days of age. At this time
close examination reveals traces of the short nestling down still
adhering to the tips of the second coat through which, on the
wings, the dark tips of the developing primaries are beginning to
push their way. the rest of the contour feathers are as yet
invisible and have not emerged from the follicles.
Mr. Sumner's plates (1933) show that at an age of 26 days the
primary quills are beginning to burst their sheaths, but the wing
coverts are still downy; at 44 days the primaries are well
advanced, and the down is rubbing off, disclosing the first winter
plumage; at 66 days the development of the wing is practically
complete.
Potter and Gillespie (1925) describes the development of their
young barn owls as follows: "Pin feather in wings appeared in
approximately twelve days. Primaries and tail feathers acquired in
five to five and a half weeks. Complete adult plumage acquired in
approximately seven and a half weeks."
Most authors state that the first winter plumage, which is the
first real plumage, is like that of the adult, but it seems to me
that there are some slight differences; the gray "pepper and
salt" markings on the upper parts are less extensive and more
mixed with buffy tints; the crown and hind neck, which are uniform
with the back in adults, vary from "cinnamon-buff" to
"cream-buff," sparingly spotted with the black and gray
spots.
This plumage is worn, without molt and with very little
abrasion until the annual, complete molt, which takes place in
both young and adult from July to November. There seem to be two
color phases in adults, which Baird, Brewer, and Ridgway (1905)
describe as follows: "Darkest: There is no white whatever on
the plumage, the lower parts being continuous light ochraceous;
the tibiae have numerous round spots of blackish. Lightest: Face
and entire lower parts immaculate snowy-white; facial circle
white, the tips of the feathers orange; the secondaries,
primaries, and tail show no bars, their surface being uniformly
and finely mottled. . . . The variations of plumage noted above
appear to be of a purely individual nature, since they do not
depend upon the locality; nor, as far as we can learn, to any
considerable extent, upon age or sex."
However, in a large series that I examined, I noted that the
males averaged lighter above and whiter below, often pure white
below, with only a few scattered small spots of sepia, and with
whiter faces. The females, on the other hand, averaged darker
everywhere, the breasts, flanks, and tibiae being often
"cinnamon-buff," deepest on the tibiae, with more,
larger, and darker spots; and the faces were more tinged with
brownish. As this was not a universal rule, however, it may mean
only individual variation, or indicate two color phases. Similar
variations were evident in the younger birds, so it is not an age
character.
Food.--All authorities agree that the
barn owl is one of our most useful birds of prey, as its food
consists almost entirely of various species of rodents that, from
their abundance and destructive habits, are a curse to agriculture
and other human interests. Dr. A. K. Fisher (1893b) reports that
"of 39 stomachs examined, 1 contained poultry (pigeon); 3,
other birds; 17, mice; 17, other mammals; 4, insects, and 7 were
empty." He says that "in California the favorite food of
the Barn Owl is a species of pouched gopher. The pouched gopher is
one of the most destructive of this group, not only to vegetable
and grain crops, but also to shade and fruit trees. The
depredations in the latter case, which consist in the gnawing or
entire removal of the roots, are the most serious as they often
result in the total destruction of groves and orchards. All the
stomachs and pellets which we have received from that state
contained the remains of this animal."
He quotes Dr. B. W. Evermann (1882) as follows: "Their
food consists principally of the gopher (Thomomys talpoides
bulbivorus) and the California ground squirrel (Spermophilus
grammurus beecheyi), both of which are so destructive to
growing crops and fruit trees on the Pacific coast. Other small
mammals, particularly rabbits, birds, and insects go to make up
its bill of fare. . . . This owl is not large, yet it must be a
very strong and courageous bird, as evinced by the fact that I
have often found in its burrows portions of the large jackass hare
(Lepus californicus) or 'narrow-gauged mule,' as popularly
known in California."
In the East the barn owl lives largely on rats and mice, and in
the South, where the cotton rat is abundant and very destructive,
its food, according to several observers, consists almost
exclusively of this rat.
Dr. Fisher (1893b) examined the nesting site of a pair of barn
owls in one of the towers of the Smithsonian Building in
Washington, and says: "The floor was strewn with pellets, and
the nest, which was in one corner, was composed of a mass of
broken-down ones. An examination of 200 of these pellets gave a
total of 454 skulls. Of these, 225 were meadow mice, 2, pine mice;
179, house mice; 20, rats; 6, jumping mice; 20, shrews; 1,
star-nosed mole, and 1, vesper sparrow (Poocaetes gramineus)."
Dr. Charles W. Townsend (1926) reports that 56 pellets of the
barn owl, found in the attic of an old rice mill near Charleston,
S. C., contained the remains of the following mammals and birds: 2
small shrews, 65 rice rats, 1 cotton rat, 7 red-winged blackbirds,
12 sora rails, and 4 clapper rails. Commenting on this unusually
large percentage of birds, Dr. A. K. Fisher wrote to him:
"Although the matter cannot be proved, I am wondering whether
rails and other birds that in a way simulate the movements of rats
and mice in the thick foliage might not be taken by accident
rather than intentionally by the Owls. This theory would seem to
have some weight because they do not molest pigeons that are
breeding in adjoining apartments or any species that are not found
on the ground around marshes or fields."
Paul Bonot (1928) tells another bird-killing story, of a pair
of barn owls on an island off the coast of California, as follows:
"There was an old cabin on the Island which had fallen partly
to ruin. Under a built-in wooden bedstead was the nest of a Barn
Owl. . . . The area covered by the bed was three inches deep with
feathers, wings and bodies of Beal Leach Petrels (Oceanodroma
leucorhoa beali). The little birds were evidently so easily
caught that there were numbers of bodies with only the heads
removed, and I collected for study three specimens with hardly a
feather misplaced. A good number of the bodies of the petrels were
rotting and inhabited by fly larvae."
It is when the young are being fed in the nest that these owls
do their best work in the destruction of rats and mice, for the
young require an enormous amount of food. W. L. Dawson (1923)
writes: "Tyler, of Fresno, found a nest containing four very
small birds and six eggs, for which the following provision had
been made: five Pocket Gophers (Thomomys), five Kangaroo
Rats (Perodipus), one Pocket Mouse (Perognathus),
and two White-footed Mice (Peromyscus)." And W. L.
Finley (1906) says:
An old owl will capture as much or more food than a dozen
cats in a night. The owlets are always hungry; they will eat their
own weight in food every night and more if they could get it. A
case is on record where a half grown owl was given all the mice it
could eat. It swallowed eight in rapid succession. The ninth
followed all but the tail which for some time hung out of the
bird's mouth. The rapid digestion of the Raptores is shown by the
fact that in three hours the little glutton was ready for a second
meal and swallowed four additional mice. If this is the
performance of a single bird, the effect that a whole nestful of
owls would have on the vermin of a community is self-evident.
Mrs. Irene G. Wheelock (1904) writes: "when the sun sinks
behind the oak trees and the shadows creep over the valleys, the
Barn Owl hurries to the nearest meadow or marsh land on a hunting
trip. If it has young at home in the nest, its flight will be
swift and noiseless, as it crosses the intervening fields at short
intervals, carrying mice, gophers, and ground squirrels. Nine mice
form a meal for the brood, and sixteen mice have been carried to
the nest in twenty-five minutes, besides three gophers, a
squirrel, and a good-sized rat."
The following items have been recorded in the food of the barn
owl: various mice and rats, nearly every available species, pocket
gophers, shrews, bats, moles, muskrats, spotted skunk (Spilogale),
and young rabbits; though birds form a small part of the food, a
number of species have been found, such as various sparrows,
blackbirds, grackles, starling, cowbird, Abert's towhee, bobolink,
swallows, warblers, wrens, red-shafted flicker, sora and clapper
rails, meadowlark, green heron, and blue jay; a few insects, such
as grasshoppers, beetles, Jerusalem cricket, and katydid, as well
as an occasional frog, should be added to the list.
Behavior.--The flight of the barn
owl is light, graceful, rather swift at times, and always
noiseless; its long, broad wings support its light body with ease
and enable it to dash quickly on its prey. It is more strictly
nocturnal than some other owls; when pressed for food to feed a
hungry brood, it starts to hunt at twilight, but, at other
seasons, I believe it prefers to hunt during the darker hours and
perhaps all through the night; its food consists mainly of such
small mammals as are active only at night. Its sense of hearing is
exceedingly acute, enabling it to detect the sound caused by the
slightest movement of its quarry; its eyes too are well adapted to
night hunting; it seems bewildered in daylight and seems to
dislike and shrink from any bright light. It is very inactive
during the day, spending the daylight hours in a dark corner in
some old or unfrequented building, in a cave, burrow, or hollow
tree, in the thick foliage of some tree, or even among the
scattered, dead leaves of a more open tree, where its motionless
attitude and its concealing coloration make it inconspicuous. In
such a situation it remains drowsily inactive all day, and often
sleeps so soundly that it is not easily aroused, until the shadows
of dusk awaken it into action again.
J. Harris Reed (1897) writes:
During the fall and winter months I have found them roosting
both singly and in colonies, depending on the size of their
roosting places, and often occupying separate cavities of the same
tree. An example of this may be found located in the woods at
Glenolden, Delaware County, Pa., which has been a favorite
roosting and nesting place for several years. . . .
On January 31, 1891, . . . I visited this tree and from the
numerous holes in its branches counted fourteen Owls fly out
during the evening. . . . Again on September 25, 1892, I paid the
place a visit, but, arriving a little late in the evening, I saw
only four Owls. . . . The Owls leave the roost very early in the
evening, often a long time before sunset, departing singly,
several minutes elapsing after the exit of one before the
appearance of another, each circling around the tree several times
before leaving, emitting a note similar to the clucking of a
squirrel, probably a call note to their companions. This habit of
leaving the roost before sunset is more noticeable during the
breeding season when the days are long and the nestlings require
food, and this no doubt accounts for their being seen occasionally
during cloudy days searching for food.
Barn owls are distinctly birds of the open country, rather than
woodland birds; and they are less inclined than other owls to shun
the haunts of man; they find their best food supplies in the open
fields and meadows, and about the barns, granaries, and other
buildings in villages, towns, and even cities. Their apparent
familiarity with human beings is, doubtless, due to the fact that
they are so strictly nocturnal in their habits and so retiring
during the day that they are seldom disturbed or even seen by
humans. Their silent coming and going is seldom observed; it is
surprising how often a pair of these owls has long remained
unnoticed in a thickly settled community; and it is well that it
is so, for, otherwise, the long-established prejudice against all
owls, or the craze to kill a curious bird, might lead some
thoughtless man or boy to destroy one of their most useful
friends.
Voice.--Potter and Gillespie (1925)
record three different calls of the adult barn owl:
"(1) A discordant scream expressing alarm. (2) A snapping of
the bill expressing suspicion and alarm. (3) A flight call,
resembling 'ick-ick-ick-ick,' apparently signifying the
bringing of food."
Grinnell and Storer (1924) say: "The notes of the Barn Owl
are of two kinds: One is a single, loud prolonged rasping sksch,
uttered only at long intervals; the other, a series of notes click,
click, click, click, click, resembling in character the notes
of a katydid, but delivered with diminishing emphasis and
shortening intervals toward the end of the series. From the
changing direction of the sounds, it is evident that the notes are
uttered in flight as one bird closely follows another."
Bendire (1892) says: "Besides the peevish scream already
mentioned, they utter at times a feeble querulous note like 'quaek-quaek,'
or 'aek-aek,' sounding somewhat like the call of the Night
Hawk (Chordeiles virginianus), frequently repeated,
only not so loud."
Joseph W. Lippincott (1917) gives his impression of the weird
notes of the barn owl as follows:
After listening night after night to the harsh screams, and
even louder growling, rattling noise he can make, sounds which in
the dark hours fairly make the shivers jump up and down one's
spine, I can well imagine that woods could seem haunted and that,
in the silent flopping flight of the big whitish bird, any
superstitious person could see a ghost or almost any uncanny being
of the visionary world. . . .
It is one of the old Owls that makes the growling rattle
which, reverberating among tree trunks, sounds almost like a
menagerie let loose. The sound seems usually to be made while the
bird is flying with, or to, its mate. When coming toward one it is
truly terrifying, particularly if in some gloomy recess of a wood.
Enemies.--The barn owl has few
enemies other than its arch enemy, man; it is deplorable that
these interesting and useful birds are so often killed because of
their supposed destruction of game birds or poultry, of which they
are seldom guilty, or because they make interesting specimens to
mount.
The great horned owl seems to be their chief natural enemy.
These large, fierce, and powerful owls have been recorded several
times as killing and devouring the gentle and weaker barn owl,
which seems to be incapable of defending itself against such a
formidable foe. Dawson (1923) says of the prairie falcon:
"The Falcon is a heartless tyrant, and in this hour of his
anxiety, he rejoices in a chance to vent his spite upon an
innocent Barn Owl. Only luck can save the Owl. Some I have seen
smashed in midair, and others merely bowled over, to rise wrathful
but silent, and scramble into cover before a second bolt should
fall."
Field marks.--The barn owl
should be easily recognized anywhere and at any time by its unique
shape and color. Forbush (1927) says" "If seen sitting,
may be recognized by its pale colors, long legs and long, white,
nearly heart-shaped face. If seen in flight, it may be told by
buffy upper plumage, light or white under plumage and long wings;
flies very lightly, often reeling from side to side."
Fall.--Throughout most of its range
the barn owl is a permanent resident, but from the extreme
northern portion it withdraws to some extent. It is also inclined
to wander about more or less irregularly in fall.
Thomas Mason Earl (1934) writes: "A curious flight of Barn
Owls was noted in 1917 just previous to the cold winter of
1917-1918. Two or three times a day for several weeks during the
November hunting season Barn Owls were brought in for mounting.
Other taxidermists had the same experience as I and I believe by a
conservative estimate 200 Barn Owls were killed in Central Ohio by
hunters, who encountered them everywhere."
Dr. Evermann (1882) says:
This owl is resident in Southern California, being somewhat
gregarious in Fall and Winter, during which seasons they frequent,
in day time, the dense foliage of the Live Oaks which abound in
the lesser canons and fringe the lower slopes of the foothills. On
one occasion I drove more than fifty of these owls from a clump of
oaks in Canada de Largo, and I have often seen from eight to
twelve dozing quietly in one tree. The cross-beams under bridges
form a favorite resort for them. Between Santa Paula and San
Buenaventura, a distance of sixteen miles, there are bridges over
as many as six barancas. . . .
In passing over this road, I have often taken the trouble to
look under the bridges, and I hardly ever failed to find from two
to six Barn Owls sitting on the cross-timbers, or on projecting
portions of the walls.
Alexander Sprunt, Jr. (1932) saw one come aboard a vessel 12 or
13 miles off the coast of North Carolina at 11 a.m. on November 1,
1931; as there was a strong offshore wind blowing at the time, the
bird may have been blown away from the land, to which it was
evidently struggling to return.
Winter.--Barn owls that linger too
far north during severe winters have been known to perish, perhaps
from the intense cold, but more likely from the lack of sufficient
food to resist the low temperature. Dr. Paul L. Errington (1931)
records such a case. In a quarry near Madison, Wis., on February
10, 1930, he found one of these owls lying dead, and a few days
later another. He says:
They were lying on the ground at the base of the quarry
face, in the crevices of which face they had been accustomed to
roost. A careful post-mortem disclosed that these birds had not
met death from shooting or from direct mechanical injury of any
sort. Though lean, they were not emaciated. Their alimentary
tracts were quite empty, except for a small amount of fecal matter
in the intestine of one of them. . . .
The presence of these two in the quarry had been known for
some months, and their pellet accumulations had been gathered from
time to time for food habits study. It had been noted, as the
winter had progressed, that the pellets had been becoming smaller,
due presumably to the protection afforded mice and shrews by
the snow. Many of the pellets last deposited contained the remains
of but a single meadow mouse (Microtus), instead of the
three to six small mammals making up a full size pellet. The owls
were apparently unable to take advantage of the winter population
of small birds; at least they had not done so.
Ivan R. Tomkins writes to me that in Georgia he has "often
flushed this species from dense cedar trees in winter and
sometimes from dry grass clumps."
Barn Owl*
Tyto alba
[American Barn Owl]
*Original Source: Bent,
Arthur Cleveland. 1938. Smithsonian Institution United
States National Museum Bulletin 170 (Part 2):140-153. United
States Government Printing Office
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