AUTHOR'S NOTE: More than any other animal group that
comes to mind, with the possible exception of snakes, owls have
become almost irretrievably intertwined with myth, misperception
and half-truths. This article is the first in a series of articles,
each of which will focus on a specific owl characteristic or behavior.
The aim of the series is to cut through the thicket of inaccuracy
and downright silliness that obscures the truth about owls.
Occasionally (not often,
just occasionally) I wonder what Martha Stewart would make of my
house and grounds. My home has evolved as my work as a raptor rehabilitator
has taken over more and more of my life. The backyard houses not
only recovering raptors, birds that will eventually be returned
to the wild. It is also permanent home base for a number of nonreleasable
birds of prey. These residents, handicapped as a result of various
mishaps, accompany me to daily educational programs. Many of my
residents are owls of several different species. In order of magnitude,
they range from a pair of huge snowy owls down to a saw-whet that
is roughly the size of a Beanie Baby. Between these two extremes
are screech owls (including, at this time of year, several babies
slated for release later in the summer), a long-eared owl, a lonely
short-eared owl that was once half of a mated pair, an elderly barn
owl, barred owls and great horned owls. These eight species, quite
conveniently, represent the eight species that can be said to live
in New England. While the snowy owl does not nest here, it is a
regular visitor, particularly to Boston's Logan Airport. The other
seven species all nest in New England, although three (barn owl,
long-eared owl and short-eared owl) are uncommon. That leaves the
saw-whet owl, screech owl, barred owl and great horned owl. These
four species are considered to be fairly common New England residents.
I didn't say they were easy to find (owls are masters of camouflage
and of the art of sitting still), but they are yearlong residents.
All these owl species vocalize in various ways
and for various reasons. Both the calls and their motivations change
with the seasons. Some calls are contact calls to mates; others
express apprehension or annoyance. In general, the best-known call
for each species is the territorial call. Owls are unusual among
birds in that both male and female produce the territorial call,
often duetting back and forth. The male's voice is almost always
deeper than the female's (the barn owl is an exception), the better
to carry through woodland. His territorial call may be longer and
more elaborate than the female's.
A territorial call is all-important to owls, which
are distinctly limited in the ways they can proclaim property rights.
In common with most birds (turkey vultures are a notable exception),
owls have a poorly developed sense of smell. Unlike mammals, therefore,
owls do not scent-mark their territory with urine or dung. Unlike
many songbirds, owls do not boast bright colors and flashy feather
patterns. Songbird males use their brilliant colors in part to delineate
their territories and to keep out rival males. Owls by contrast
are a subtly colored group, modestly attired in shades of cream,
brown, black and gray. To establish and hold a territory, they must
rely on sound.
There is a distinction to be made between an owl's
call and a songbird's song. Songbirds, also known
as passerines, may produce complicated, multi-note passages that
sound pleasantly musical to us. Such a complex vocalization is a
song. Owls, by contrast, typically produce less complex sounds.
Owl calls may vary in pitch, intensity, number and emphasis (they
may even contain regional accents), but they lack the elaborate
structure of true birdsong.
Still, owl calls vary tremendously, as you might
observe by concealing yourself in my backyard some evening in late
March. This is the time of year when wild owls are moving through
the neighborhood and my residents, with their superb hearing, are
aware of the presence of strangers. They respond with territorial
calls, each species with its own signature call. My residents also
respond to one another, each setting the others off, and there are
nights when my yardful of owls will all be vocalizing in a kind
of owlish call-and-response (these are nights when I don't get a
great deal of sleep).
The resultant chorus, aquiver with eerie wails
and punctuated with staccato barks and yelps, is living (and noisy)
proof that owls do not necessarily hoot. In fact, some owls, like
the barn owl, cannot produce a sound that resembles a hoot,
although they certainly vocalize. Among my resident owls there is
only one species that produces what might be termed a classic hoot.
That would be the great horned owl, whose booming territorial call
is routinely dubbed into movie soundtracks to invoke an atmosphere
of foreboding. This, by the way, is not a new technique. Long before
the birth of the cinema, writers like Shakespeare were inserting
owl cries into their stories to presage sinister events.
Impressive as my great horned owls sound, however,
they are not my loudest owls. Neither, for all their bulk, are the
snowy owls, whose vocalizations often sound as though they're wrapped
in a thick sweater. My loudest owls, the ones that can stop all
the others in mid-cry, are the innocent-looking barred owls. Of
the 19 owl species found in North America, the barred owl produces
the widest range of sounds, and some of these are loud. Unlike
the muffled tones of the massive snowy owls and great horned owls,
barred owl vocalizations have an emphatic, in-your-face quality.
While the different owl species have characteristic
vocalizations, all owls hiss and beak-clack to express annoyance
or fear. Even baby owls will hiss like snakes if they feel threatened.
The beak-clack also begins in the nest, and is not just a simple
matter of snapping the two mandibles together. The lower mandible
is pushed beyond the curve of the upper mandible and then forcefully
snapped back into position with a clearly audible clack.
Barn owls actually use their tongues to produce the snapping sound.
However, these are generalized owl sounds that won't help us to
identify different owl species. Let's return to my yardful of resident
owls and listen in on some of the calls produced by the different
species. These species-sound descriptions aren't meant to be complete
records of every vocalization the different species are thought
to produce. They are meant to be records of sounds I've actually
heard my birds produce. With these eight species-sound descriptions,
I hope to prove three things:
1) My observations of what my resident owls
sound like frequently do not square with descriptions in reference
books. I'm tempted to wonder if much of what is reported might be
based on mishearing or misinterpretation or misidentification or
mis-something. The incorrect information is then repeated
in print without being checked for accuracy.
2) Owl calls not only vary greatly from species
to species, the different genders sound different, and there is
regional and individual variation as well.
3) Not all owls hoot. Even the great horned
owl, which does hoot as a territorial call, produces other, very
different calls to express anger, warning or fear.
From the smallest species among my resident
owls up to the largest, here are the sounds I can hear at different
times of the year in my backyard.
Northern Saw-whet Owl (Aegolius
acadicus)
Weight: 3-4 ounces
Length: 7-8 ½ inches
Wingspan: 17-21 inches
While I have been rehabilitating raptors
for over twenty years, I have cared for relatively few saw-whet
owls. Only nine in over two decades, while my screech owl, barred
owl and great horned owl patients have been far more numerous (the
screech owl is by far the owl species I rehabilitate most often,
followed by the great horned owl). Saw-whets tend to live and hunt
in dense evergreen forests or in red maple / cedar / hemlock bogs,
and they are rarely seen, even by avid birders. Nor does this species
seem to hunt for insects attracted to street lights in the summertime,
as screech owls are known to do. Studies done in Massachusetts with
mist nests show that this engaging little owl with the high forehead
and gem-like yellow eyes is more common than was previously thought,
and gets closer to human habitation than was previously known. Still,
the saw-whet seems to prefer to hunt in wooded areas and is not
hit by cars nearly as often as our other three common resident owls.
Of the nine saw-whets I've cared for*, two males (smaller than the
females, as is the case with almost all owl species) and one female
were nonreleasable and so became permanent residents. One male lived
with me for nine years. So what sounds did these diminutive owls
produce?
I'll start off by saying that I don't subscribe
to the oft-repeated story that saw-whet owls derive their common
name from the fact that they make a sound like a lumber saw being
sharpened with a file. This story can be traced back to none other
than John James Audubon, who spun the tale in his book Ornithological
Biographies. According to Audubon, who at one time owned
a mill in Kentucky, one summer day he heard a scraping sound produced
by a bird and coming from inside his mill. Although he did not get
a good look at this bird (the mill foreman, on the other hand, did
see the bird close up and came up with a totally different identification),
Audubon thought he knew what it was from the sound it produced.
That, he promptly decided, was the call of a saw-whet owl. Therefore,
the mill's avian occupant was a saw-whet owl. It seems to me that
Audubon jumped rather wildly to that conclusion, since he hadn't
gotten close to the bird. More important, as far as I can find out,
while Audubon knew that New Englanders called a certain tiny owl
the saw-whet, neither he nor anyone else had any evidence that New
Englanders named the owl that because they thought the owl's call
sounded like a saw being whetted.
There is more evidence against Audubon's mystery bird being a saw-whet.
The incident took place in the summer, when every reference book
indicates that saw-whets are quiet. My own observations bear this
out: saw-whets give the territorial call only in the spring, and
then they fall silent. When saw-whets do call it would be at night,
and Audubon heard this owl call by day. The location was Kentucky,
which is part of the saw-whet's range only during winter migration,
and last but by no means least is the evidence of the mill foreman,
who (unlike Audubon) did get a good look at the owl. He called it
a "screech owl," which is what the barn owl was appropriately
called by rural people. Barn owls do screech, and they routinely
roost and nest in buildings, which is why they're now called barn
owls.
Very well then, so Audubon cobbled together a
story that is full of ornithological holes, but such is the man's
reputation that the story is still believed. If his tale is untrue,
as I think it is, what's the explanation for the saw-whet's unusual
name? My etymology is not based on an original thought, but I can
bolster someone else's theory with original observations. Julio
de la Torre, writing in Owls: Their Life and
Behavior, points out: "As Davis Finch pointed out years
ago, the name of the owl is almost certainly an anglicization of
the French word chouette (shoo-ET), a word universally used
in France and French Canada to refer to any small owl. La
chouette is indeed what farmers in the Gaspe and elsewhere
in French-speaking Canada call this little owl, which for them is
a backyard species." I might add that chouette is also
used by French speakers to mean "nice," "fine"
or "something particularly good of its kind." The saw-whet
merits those descriptions. To my eyes, at least, this elfin owl
with the expressive face is the cutest of the 19 North American
owl species.
And how did chouette become saw-whet?
Well, foreign-language words that enter the English language often
end up mispronounced. When Yankees, perhaps lumberjacks or trappers,
came in contact with French speakers, either in Maine or Canada,
they picked up the name chouette for this little owl, but
turned the pronunciation into saw-whet. The saw-sharpening
story is a misguided attempt to force together an implausible story,
an implausible owl and an implausible location.
Okay, so now I've got that off my chest. What call does the saw-whet
owl produce? Well first of all, as far as I can tell, it's only
the male that makes the territorial call, and he only produces the
sound in the spring - from March to May. This sound is described
by many experts as a TOOT or a TOO. To my ears (this may be the
way I hear, or perhaps different saw-whet owls sound different)
the call sounds like a POOT or POO, and the males repeat the bell-like
note rapidly: POO- POO-POO-POO-POO-POO. The most consecutive notes
I've counted were twenty-two. Then the male stopped, was silent
for a few seconds, and then began again. The calling starts around
8 PM and continues, at intervals, until 5 AM. I have never heard
this call by day, nor have I ever heard it at any time of year other
than springtime. Either the POOT call is territorial or it is a
call to contact females, or it is both. One clue that the call is
a territorial/contact sound is its carrying quality. The POOT call
is designed to be heard a considerable distance from the caller.
When my male is calling, I can cross the street and still hear the
POOTs coming from my backyard, which is at least the length of a
football field away. The tone is clear, unmuffled, quite unlike
the hoot of a great horned owl.
The other saw-whet sound I'm familiar with is produced all year
long by both genders. The annoyance call is not loud, not designed
to carry a long distance, nor is it a clear note, as the territorial
call is. It is a metallic buzz, NNAAA, like that produced by a very
small dentist's drill. Its meaning, roughly translated, is: go away
and leave me alone. It is produced when an intruder (another bird,
a squirrel or a person) gets too close to the owl. Both sexes also
hiss and beak-clack when disturbed.
* All nine were impact-injured, meaning they
were struck by something, and all nine might have been hit by cars.
Five were picked up by the side of roads and were almost certainly
struck by vehicles.
Eastern Screech Owl (Otus
asio)
Weight: 6-7 ½ ounces
Length: 7-10 inches
Wingspan: 18-24 inches
The screech owl should
sue for libel. The New World screech owls (there are several related
species in Central and South America, as well as in North America)
were so named by European settlers because of a fancied resemblance
to the barn owl. The bird Americans now call the screech owl doesn't
screech, but the bird Americans now call the barn owl, which the
Europeans called the screech owl, does screech. Well, that's unenlightening,
so let's see what we can do to clear up the confusion.
Screech owl adults of both sexes vocalize, but
the territorial/contact call is most definitely not a screech, or
anything like a screech. It is an eerie, tremulous warble, a quavering
WOO-OOO-OOO-OOO. The male's voice is lower than the female's, and
a pair will duet back and forth, sometimes calling at the same time.
The call is not far-carrying, and its origin is very hard to pin
down. I've cared for dozens of screech owls over the years and always,
as I watch the throat of a vocalizing bird pulse, I'm at a loss
to explain the tonal quality of this call. It seems to come from
everywhere and nowhere. Some reference books describe this as a
ventriloquial effect, but this isn't exactly right. When a ventriloquist
"throws" his or her voice, the voice seems to come from
somewhere other than the real speaker's vocal cords. When a screech
owl calls, the sound seems to have no origin. If you hear the sound
in your area (it's usually produced at night, with peaks around
dusk and dawn), don't rush out expecting to find the owl. It will
be hidden and will not reveal itself to you. And the call will not
give its location away, since the call's quality disguises its true
origin. This has survival value for a small owl with many predators,
including larger owls.
A pair may duet as they care for the young in
spring and summer, but the peak time to listen for this call is
in early spring, as the parent birds are reaffirming their pair
bond and delineating their territorial boundary lines to migrating
birds moving through the area.
A call often described as a whinny is also a contact
call, but it is not a territorial call. It is a specific vocalization,
and it conveys apprehension. It is used when a screech owl sees
or hears something threatening, and it is a warning to other screech
owls. Like the territorial call, this sound has an eerie, quavering
quality and I'd transcribe it like this: WHOOOOOoooo. It rises and
falls, and it is not given repeatedly. A screech owl making this
"miniature horse" whinny is a perturbed bird. Both sexes
make the sound when they feel apprehensive, and I can't detect a
difference in pitch. When a screech owl is so frightened that it
freezes in position (as when my residents catch sight of a cat trying
to scale my stockade fence), it gives a soft, sad OOO, which I interpret
to mean "imminent, serious danger." When annoyed both
sexes will chitter, a buzzing sound that means "back off."
The young produce a WHEEP begging-food call which ends as they become
independent of their parents in mid or late summer.
A screech owl produces a variety of calls, but
as far as I've heard, there's nothing resembling a screech among
them.
Long-eared Owl (Asio otus)
Weight: 7 ½ - 11 ½ ounces
Length: 13-16 inches
Wingspan: 36-42 inches
We now move from two small
owls to the medium-sized owl category. The long-eared owl and the
short-eared owl are congeners, close relatives that are placed by
taxonomists in the same genus. The question is, are the vocalizations
of these two relatives similar?
I should point out, first of all, that the long-eared
owl and the short-eared owl live in vastly different environments.
The short-ear is an open-space bird, hunting for mice and voles
over meadows, farmland and marshes. The secretive long-ear, by contrast,
is a woodland owl, a master at concealing itself in conifers by
day, while floating buoyantly through the forest by night in search
of woodland mice like deer mice and white-footed mice. Because of
its strict nocturnal habits and because it is completely tied to
forest life, the long-ear, named for long tufts of feathers positioned
almost directly above its eyes, is rarely seen and even more rarely
handled by rehabilitators. In my twenty-three years as a raptor
rehabilitator I've only cared for two long-eared owls. One, a probable
female (given the bird's dimensions it might be a large male or
a small female), has produced one of the most interesting owl vocalizations
I've ever heard.
The long-eared owl, according to my reference
books, does hoot upon occasion, and it would seem that the contact/territorial
call sounds like this: KWOO or KWOO-KWOO. Julio de la Torre, writing
in Owls: Their Life and Behavior,
characterizes this call as "remarkably pure and musical, given
in long, leisurely series by both sexes…." Well, I look
forward to someday hearing this musical sound in the wild, because
the one vocalization I've been hearing from my patient is an emphatic
and totally unmusical yyyYOW! The call begins low and builds to
a spat-out snarl. I'm unsure about the meaning of the call. It's
produced when the bird sees me approach as well as when I'm concealed.
It may express annoyance at seeing a trespasser (me or another bird)
moving near the owl's cage, which is also its territory. This growly
sound has a distinctly feline quality to it, and no other owl I've
worked with produces a call anything like it, except the long-ear's
close relative, the short-eared owl.
Short-eared Owl (Asio flammeus)
Weight: 9-15 ounces
Length: 13-17 inches
Wingspan: 38-44 inches
The beautiful short-eared owl is glimpsed
far more often than the long-ear both because of its diurnal hunting
habits and because it hunts over open spaces. While this tawny-colored
owl does not nest in my area of Massachusetts - indeed, it no longer
nests anywhere on mainland Massachusetts, restricting its breeding
areas in this state to Nantucket, Martha's Vineyard, and to a few
smaller islands positioned between these two large ones - it does
migrate along the Connecticut River, and I've cared for a male and
a female. The two were housed together in hopes that they would
breed. While that never happened, the two did seem to form a pair
bond and coexisted peacefully (or semi-peacefully) for some years.
The noises these two produced were all unpleasant-sounding, cat-like
and growling. I never heard anything that could be described as
a hoot, although according to my reference books the courtship call
might be rendered BOO-BOO-BOO. The call I heard daily from the male
was a rasping eeeYERP! which I presume was a territorial vocalization.
He spat the call out whenever he saw me approach, and then the female
would back him up by producing the same call in a shriller tone.
During the day or night both birds commented on birdlife around
them with a snarling yeeOW! call that was so feline-sounding that
the first time I heard it I promptly began patrolling the yard,
searching for a trespassing cat. The pair would yeeOW! to each other
when they got on each other's nerves. In looks, particularly when
these owls raised their short head tufts in alarm, and in vocalizations,
the short-eared owl is the most cat-like owl I've personally dealt
with.
My pair were both wing-impaired birds, so I never heard them produce
a sound that wild male short-eared owls are noted for. During courtship
flights, the agile male will swoop and dive to impress the watching
female. At the beginning of each dive he claps his long wings together
under his body, producing, says Julio de la Torre, "…a
sound much like the fluttering of a flag" in a high wind. I
hope someday to hear that sound in the wild. One other non-vocal
way the short-eared owl communicates is with its eyes. Like the
long-ear, the short-ear has intensely yellow eyes set off by black
patches. The black, like dramatic eye makeup, emphasizes the eyes,
and the owl will glare directly at a trespasser to its territory.
I believe the eye glare, in both the long-eared and short-eared
owl, is a threat display.
Common Barn Owl (Tyto alba)
Weight: 10-20 ounces
Length: 14-21 inches
Wingspan: 41-47 inches
We come now to the last
of the medium-sized owls being profiled for this article. Here is
the owl that should be called a screech owl. The barn owl's
syrinx, or voice box, is made in such a way that it cannot hoot.
But boy, can it screech. The only barn owl I've handled is a male
that is a longtime permanent resident. Barn owls in Massachusetts
are at the farthest extension of their breeding range and are uncommon
as nesting birds in this state. So my experience with the species
has been limited to this one male, but he's been a source of endless
wonderment, since his behavior and his vocalizations are so different
from other owls. Barn owls and their tropical relatives the bay
owls are placed by taxonomists in the Tytonidae family, while all
other owls, called "typical" owls, are placed in the Strigidae
family. Barn owls differ from other owls in build and in bone structure,
and their calls are decidedly unlike "typical" owl calls.
The call I hear the most is best characterized as a snore. Iroquois,
my resident barn owl, makes this as a greeting utterance. He also
produces a very engaging cricket-like chirp, but this can escalate
in volume and intensity to indicate annoyance. During the breeding
season he will make a specialized call that I never hear outside
the nesting period. For which I'm grateful, because the call can
go on with nerve-racking monotony for several minutes at a time.
I'd render it BLUH-BLUH-BLUH, and the call is accompanied by foot
stomping, done while the owl is on the floor of his cage. I've near
heard the call made from a perch. Typically, Iroquois flies down
into a corner of his cage and then foot-stomps and calls for several
minutes. This, I suppose, is both a territorial and a contact call,
designed to attract a female and repel rival males.
The shriek the barn owl produces is so unowl-like
and so startling that I have to wonder if it's designed to scare
prey and induce a mouse or vole to move, so the barn owl can then
home in on the sound of the rodent's movements. This rasping sssSEEK!
is emphatic and far-carrying, and Iroquois has a habit of making
it when I least expect it. That call has made me drop many a filled
waterbowl as I go about my cage-cleaning chores in the yard. This
vocalization may be made in response to other owls and it may be
territorial in nature. Whatever its meaning or intent, it certainly
gets one's attention. Shakespeare called the barn owl "the
owl that shriek'd," and, as usual, the man was right.
Barn owls also hiss and beak-clack, but during
the beak-clack they visibly snap their tongues, something I've never
seen another owl species do. The beak-clacking is often accompanied
by a strange rolling of the head from side to side. This slow-motion
swaying is done with the face directed downward, while the tongue
THWAPS rapidly. Clearly a threat display, although the mechanics
of this display have always puzzled me. If you're threatening something
that poses a potential hazard, is it wise to take your eyes off
it?
Barred Owl (Strix varia)
Weight: 11-22 ounces
Length: 16-24 inches
Wingspan: 38-50 inches
The barred owl qualifies
as a large owl. It also qualifies as North America's champion owl
vocalizer, both in range of sounds produced and in volume.
The usual transcription of this owl's contact call is: Who cooks
for you? Who cooks for you all? Birding and rehabilitator friends
tell me that they can actually discern this phrasing in the barred
owl calls they hear. I never have, and I'm quite sure that there
is individual and regional variations in bird vocalizations. My
barred owls rarely give the eight-hoot call that is considered so
typical that the barred owl is called the "eight-hooter."
My resident barreds shorten the sequence to four very loud, very
emphatic syllables: hoo-hoo-hoo-HOOaww! The last syllable is characteristic.
The downward aww, like the bray of a demented donkey, is only made
by a barred owl.
Earlier in this article I made the statement that among the Northeast's
eight resident owl species only the great horned owl gives what
I would call a "classic" hoot. While it is true that the
barred owl does indeed hoot, the call has a very different quality
from the great horned's booming foghorn. Barred owls have a nasal
quality to their hoot, and there are echoes of other animals in
their commonest call - a chimpanzee, a dog, a burro with a stomach
upset. Great horned owls sound as we imagine an owl should. Barred
owls, on the other hand, sound like lots of things.
Although this species has the reputation for producing
a variety of calls, from barks to groans, the only other sound I've
heard my barred owls produce is a hair-raising scream. This is not
the rasping shriek of the barn owl. This is an all-too-human-sounding
scream, as though a person were in terrible pain. This call, from
my experience, is always produced at night (the HOOaww call may
be given by day, particularly when thunder and/or rain are imminent),
and I'm not sure of its significance. It is usually given singly,
not in sequence, although the male may vocalize and then be answered
by the female's scream.
Of all my residents owls, the barred owls are
the loudest and they win every vocal argument with my other species.
On a March night when my snowy owls, great horned owls, screech
owls and my lone saw-whet owl may all be vocalizing back and forth,
suddenly there erupts an almighty HOOaww! from the barred owl cages.
Even the male snowy owl falls silent. Translation? "Everybody
shut up!" And, for a short time at least, everybody does. Territorial
competition among owls is probably based partly on how loud a bird's
calls are. Biggest mouth wins.
Great Horned Owl (Bubo virginianus)
Weight: 3-4 ½ pounds
Length: 18-25 inches
Wingspan: 35-55 inches
The deep booming hoot of the great horned
owl is, at least in my mind, the quintessential owl call. The great
horned owl sounds the way an owl is supposed to sound. The contact/territorial
call is full and satisfying, accurately hinting at the size and
power of its owner. This is the bird that rules the skies of the
Western Hemisphere at night. While the snowy owl is somewhat larger,
the snowy has a limited northern range, while the highly adaptable
great horned owl is found from Alaska to the tip of South America.
And while I've never seen a battle between a great horned owl and
a snowy owl, I'd bet on the great horned owl if such a fight ever
occurred. The great horned owl is a fiercely determined hunter,
known to take mammalian prey up to and including porcupines. Avian
quarry can include swans, herons and turkeys. This strongly territorial
species is a known limiter of other raptor species, including the
swift-flying peregrine falcon. After 1972, when the use of the deadly
pesticide DDT was banned in the United States, scientists waited
for the peregrine falcon to reestablish itself in its old haunts.
Wiped out as a breeding bird in the eastern half of the U.S. by
DDT, the peregrine was reintroduced to the East through captive
breeding-and-release programs. As of this writing, Massachusetts
is home to six pairs of peregrines, but not one is nesting outside
of a city. The old territories have been taken over by great horned
owls (and, in at least one instance, by ravens) who are fully capable
of killing young peregrines. The great horned owl is a top predator,
one feared by all other North American raptors. As proof of its
power and the respect with which it is held by other birds, a pair
of great horned owls nested in the winter/spring of 2002 in a great
blue heron rookery along Route #2 in Massachusetts. The two young
were being raised successfully, which means that the parents were
flying unmolested past numerous great blue herons on their daily
trips to and from the hunting territory.
So does this awesome predator always hoot? Usually, yes. A generalized
contact/territorial call might be written WHOOO-who-who. The number
of hoots varies, as does the accented beat. The last two hoots in
the sequence are usually very emphatic and more drawn-out than the
middle calls, so the male's deeper, more complex vocalization might
look like this: WHO! who-who-who WHO! WHO! The female also gives
voice to the contact/territorial call. Her pitch is higher than
the male's, and the number and arrangement of her calls is shorter
and simpler than his. A mated pair will duet during the early-winter
courtship period. As actual mating nears, the pair will call together,
although not in unison. The different arrangement of the male's
and female's calls is always discernible, as is the difference in
pitch.
This mated-pair duetting can get loud, but never
as loud and nasally emphatic as a barred owl call. There are two
other great horned owl calls produced for specific reasons that
are real attention-getters. One is a lunatic laugh, which seems
to be made by the male during the courtship calling. Possibly it
is meant to be romantic, an enticement to mating. Possibly it demonstrates
virility. I'll tell you what I'm sure of - it's a very disturbing
sound. Twice my resident male great horned owl has made this call
by itself, without the context of the contact/territorial call.
Both times I went charging out into the yard, convinced that a maniac
had broken out of the asylum and had irrationally chosen to camp
out among my cages. Another call with a disturbing edge to it is
a rasping bark: neeYARK! Some reference books describe this as a
nestling great horned owl call, and since my male is an imprint,
socialized to people, perhaps he occasionally reaches back to his
babyhood and produces this emphatic vocalization. Great horned owl
young, like other owl nestlings, typically make a wheezy EEEP! to
beg food from their parents. The pitch and pronunciation is individual,
and I can tell the difference among three young calling at the same
time. The young also hiss and beak-clack when disturbed.
Snowy Owl (Nyctea scandiaca)
Weight: 3-3 ¾ pounds
Length: 20-27 inches
Wingspan: 54-60 inches
Of the eight species of North American owls
I've handled, this one, the largest, is also the least vocal. Virtually
all the sounds I've heard are produced by the male, and the typical
call is a definite bark, like a rottweiler with a sore throat: BOOF!
The call is not produced in a discernible sequence, like the hoots
of the great horned owl. Indeed, I've not been able to work out
any kind of pattern to the male's vocalizing. The "boof"
call is produced at any time of year, and may be in response to
what he perceives as a territorial threat. The female very occasionally
has made a similar sound, but it does not seem to be in response
to the male or any of his actions. My female, who insists on making
a nest every year (even though she and the male are not housed together),
produces a clear whistle from time to time. She only does this when
sitting on her nest, so the vocalization is tied in with the nesting
season.
Snowy owls hiss and beak-clack like other owls to convey threat
or annoyance. They also have a non-vocal way to express those emotions
that is unique to the species. Male and female have deep red mouth
linings, and when they're disturbed they open their mouths wide
and confront the threat head-on. Before I acquired these snowys
I'd seen many photographs of wild and captive birds demonstrating
the mouth-gape but hadn't realized the significance. Now since I
see the red mouth-gape on a regular basis, I'm all too aware of
its message: BACK OFF! Snowy owls don't hoot, but they can be very
effective communicators.
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