Voices of North American Owls - Cornell University

Voices of North American Owls
This comprehensive 2-CD audio guide presents nearly 200
recordings of North America’s 19 regularly occurring owl species
plus two rarities. With a booklet containing detailed text and
color photographs, this collection illuminates for the first time
the diversity of owl vocalizations in North America.
“The best of the best, my kind of CD production, as it takes me
well beyond identifying owls by their sounds to understanding
owls by their sounds. I can’t wait till my next owl encounter, as I’ll
listen in a whole new way.”
Donald Kroodsma, author of The Singing Life of Birds
“Cornell’s Voices of North American Owls is the most comprehensive
and detailed treatment of this subject to date and will serve as the benchmark reference for years to
come. It documents that owl vocalizations are more complex than we imagined, and will both train
and stimulate a new generation of owl biologists and naturalists to better understand, appreciate,
research, and conserve these fascinating creatures. Find a place in your CD collection for this
volume—you will not regret it!”
Dr. James R. Duncan, author of Owls of the World
“Voices of North American Owls opens up the world of the night—a treasure-trove of strange, lovely and
sometimes hair-raising owl vocalizations, from the courtship wing-clap and hooting of a pair of Long-eared
Owls to the tooting food-delivery calls of a Northern Saw-whet Owl in an eastern forest and the chatter of
an Elf Owl in the Arizona desert. By far the most comprehensive collection of North American owl vocalizations
ever produced, it features not just common territorial songs, but many lesser known vocalizations,
including alarm calls, juvenile food-begging cries, contact calls, and more. Voices of North American Owls is
a must for anyone who wants to know what goes bump (and toot, and screech, and hiss) in the night.”
Scott Weidensaul, author of Living on the Wind
Cornell Laboratory of Ornithology
www.birds.cornell.edu/macaulaylibrary
ISBN 0-938027-66-2

2
“I rejoice that there are owls. Let them do the idiotic and maniacal hooting for men.
It is a sound admirably suited to swamps and twilight woods which no day illustrates,
suggesting a vast and undeveloped nature which men have not recognized. They represent
the stark twilight and unsatisfied thoughts which all have.”
Introduction
Owls have persisted in man’s cultural
consciousness since the beginning of
time. From the earliest cave paintings
through modern times, owls have
appeared in artifacts, myth, folklore,
and legend. They represent a broad
spectrum of meanings for different
cultures and individuals around the
world—regarded by some as symbols
of wisdom and godliness, and by
others as harbingers of death. Few
birds or other animals capture our
minds and imaginations to the degree
that owls do.
Our emotional response to owls is
often attributed to their human-like
Henry David Thoreau, Walden
appearance. Their large forward-facing
eyes and expressive faces have contributed
greatly to the lore surrounding
them. Less often considered, but
perhaps even more significant, are the
sounds owls make. From the earliest
hunter-gatherers sitting in darkness
around a fire, to scientific researchers
today, owl sounds in the night have
presented a mystery to be feared or a
question to be answered. Remarkably
we still know little about owls and the
meaning of their sounds. This compilation
aims to shed new light on the
intricacies of owl vocal behavior and
to aid ornithologists and bird- watchers
in detecting and identifying these

denizens of the night. It is also hoped
that the listener will gain a greater
appreciation for owls and the importance
of conserving the habitats where
they live.
The Sounds Owls Make
Primarily nocturnal, and often living
in dark forested environments, owls
rely heavily on sound both to find
prey and to communicate. Most owls
are built to receive sound, enabling
them to locate prey aurally with great
accuracy. They have also evolved
rich repertoires of vocalizations for
communicating in the dark. These vocalizations
are inherited and in many
instances convey precise meanings to
other owls. Upon hatching, young
Barred Owls give specific calls that
communicate hunger to their parents
and stimulate the adults to feed
them (Disc 2, Track 3). Though the
3
character of this vocalization changes
as young birds grow, it still carries its
precise meaning; adult females use it
to solicit food from their mates. (Disc
2, Track 1).
Owls use songs primarily for territorial
proclamation, territorial defense, and
mate attraction and bonding. Songs
generally consist of multiple notes
with intervals between notes usually
less than twice the note duration.
Typically they have high harmonics.
Owl calls are used in a variety of other
contexts such as begging, alarm, or aggression.
Calls are generally single notes
with longer intervals between notes.
With a few exceptions, calls generally
lack harmonics. Calls often vary significantly
depending on an owl’s age, motivation,
or stimuli. It is also common
for a vocalization seemingly identical
to a species’ song, or a derivative of that
vocalization, to be used as a call, such
as hooting by male Long-eared and
Snowy owls in nest defense.
Although most owl species’ songs are
unique, such as the low hooting of a
Great Horned Owl or the whinny of
an Eastern Screech-Owl, some calls
appear to be used in similar contexts
by many owl species. The discomfort
call, often referred to as a “chitter” by
researchers, is most often uttered by
both adults and young when in close
association with other owls or when
being handled by researchers. This call
commonly communicates discomfort,
including hunger, but is also used
during mutual preening (allopreening),
food transfers, and copulation.
Most owl species seem to produce
analogous variations of this call under
similar stimuli. Other similarities in
calls of different species suggest other
analogous call-types may exist. A
system of naming and classifying these
vocalizations is useful for standardizing
the way that we talk about owl
vocalizations. Some suggestions for
alternate naming of vocalizations have
been included in this production.
About This Compact Disc Set
Some selections on this CD were
made strictly to illustrate particular
vocalizations, some to illustrate
behavioral sequences, and others for
sheer listening pleasure. Therefore
the length and quality of recordings
within this production vary. Although
every effort was made to include all
known vocalizations for each species,
many vocalizations remain unrecorded
or unavailable. There are also vocalizations
that have yet to be described or
have only been described phonetically.
This has made identification of many
previously described calls and associat-

ed behavior problematic. Additionally,
observing behavior associated with
vocalizations of nocturnal animals
is inherently difficult. Therefore the
repertoire presented for each species
should be considered incomplete and
the accompanying text for each vocalization
a conservative interpretation
of the available literature. Behavioral
contexts are described when known
but should not be considered the
only circumstances in which a species
may use a particular vocalization.
Though names given by researchers
to some vocalizations can be misleading
as to the function, we have tried
to include the names by which many
of the calls presented here are commonly
known. For a more comprehensive
written treatment of owl
vocalizations, consult the additional
references listed in this booklet.
4
Playing Recordings In The Field
The greatest care should be taken
when using recordings of owls and
other birds in the field. Playback
of these recordings should be done
responsibly, particularly during the
breeding season when owls are most
vocal. Some recordings on this CD,
especially distress and alarm calls, could
cause undue stress and should never
be played in the field. One of the most
fulfilling ways to experience owls at
night is simply to go out and listen.
Acknowledgements
We extend our thanks and gratitude
to those individuals and organizations
that have helped us in the development
of this audio guide. Tom Weber of
the Florida Museum of Natural History
(FMNH), Jill Soha of the Borror
Laboratory of Bioacoustics (BLB) at
The Ohio State University, and Chantal
Dussault of the Canadian Museum of
Nature (CMN), kindly searched their
archives and provided unique recordings
for this production. Thank you to
Jack W. Bradbury and Sean O’Brien
for reviewing the text in its entirety and
providing valuable insights and additions.
Our sincerest thanks also to those
who provided their expertise, time, and
knowledge in reviewing portions of
the species text and associated recordings:
Frederick R. Gehlbach, James R.
Duncan, Robert W. Nero, Glenn A.
Proudfoot, Denver W. Holt, Eric D.
Forsman, D. Archibald McCallum,
Bernard Lohr, Karla Kinstler, Richard
J. Cannings, Gregory D. Hayward,
Douglas E. Trapp, and Tony Angell.
An additional thanks to Glenn A.
Proudfoot and Bernard Lohr for their
visits to the Macaulay Library during
the development of this audio guide,
and for archiving new field tapes for use
in this production. Finally, our sincerest
gratitude to the contributing recordists.
Without their nocturnal forays, this
guide would not have been possible.
Contributing Recordists
Arthur A. Allen, Harriette Barker, Charles
M. Bogert, Kent Bovee, Meredith Bovee,
Gregory F. Budney, Greg Clark, Richard
J. Clark, Benjamin M. Clock, Kevin J.
Colver, L. Irby Davis, Robert W.
Dickerman, Lang Elliott, William R.
Evans, Steve Farbotnik, Robert C.
Faucett, William R. Fish, J. R. Fletcher,
Frederick R. Gehlbach, William W.
H. Gunn, David S. Herr, Wilbur L.
Hershberger, Virginia Huber, Albert
Karvonen, Geoffrey A. Keller, Peter Paul
Kellogg, Thomas Knight, Wendy Kuntz,
Greg Lasley, J. David Ligon, Randolph S.
Little, Bernard Lohr, Stewart D.
MacDonald, Curtis A. Marantz, Joseph
T. Marshall Jr., Brian J. McCaffery, D.
Archibald McCallum, Hugh P. McIsaac,
Matthew D. Medler, Rosa Meehan,

Martin C. Michener, Sean O’Brien, Sture
Palmer, Leonard J. Peyton, Tim Price,
Glenn A. Proudfoot, George B. Reynard,
Jeffrey Rice, Robert Righter, Andres
M. Sada, Thomas G. Sander, David T.
Spaulding, Sally Spofford, Robert C.
Stein, Charles A. Sutherland, Gerrit Vyn,
Scott Weidensaul, and Steven G. Wilson.
Resources And Bibliography
The Birds of North America Online
Johnsgard, P. A. North American Owls:
Biology and Natural History, 2nd edition.
Washington, D.C.: Smithsonian
Institution; 2002.
Duncan, J. R. Owls of the World: Their
Lives, Behavior, and Survival. Buffalo,
NY: Firefly Books; 2003.
5
König, C., F. Weick, and J. Becking.
Owls: A Guide to Owls of the World.
New Haven, CT: Yale University
Press; 1999.
Owl Research Institute, an organization
dedicated to owl research,
conservation, and public education
The Owl Foundation, a center for the
rehabilitation of Canadian owl species
and the behavioral observation of
permanently damaged wild owls in a
breeding environment
A Note To Recordists
And Researchers
This CD represents a first step in classifying
and disseminating the songs
and calls of North American owls.
Researchers and recordists are invited
to contribute their recordings for future
editions of this guide and to provide
any written insights into the material
presented here. We hope that this collection
will serve as a working reference
for those describing and studying owl
vocalizations and behavior.
For production purposes, changes to
inter-song interval and other edits
have been made to some recordings.
For research purposes, please contact
the Macaulay Library to obtain source
recordings. Soon our complete audio
catalogue will also be available for
listening and spectrographic analysis at
.
The preservation and study of acoustic communication
recordings of birds and other
animals is the focus of the Macaulay Library
(formerly the Library of Natural Sounds) at
the Cornell Laboratory of Ornithology. To
learn more about how wildlife recordings are
made, how to participate in this work, and
how to become a member of the Cornell
Laboratory of Ornithology, please contact us.
Macaulay Library
Cornell Laboratory of Ornithology
159 Sapsucker Woods Road
Ithaca, NY 14850
Telephone: (607) 245-2404
email: macaulaylibrary@cornell.edu
Interpreting and conserving the earth’s
biological diversity through research, education,
and citizen science focused on birds

Barn Owl Tyto alba
The Barn Owl’s screams, pale ghostlike appearance,
and inhabitation of abandoned
buildings, farms, and church belfries have
probably contributed to superstitions about
owls around the world. Barn Owls are vocally
active when breeding and use a wide
repertoire of acoustic signals. Most of their
vocalizations fall into the category of hisses
and screams, with different calls often grading
into each other. This makes it difficult to
distinguish between subtly different calls, describe
them phonetically, and associate them
with a specific behavior. Female screams are
generally huskier and less consistently given
than male screams, but sexing individuals
based on this is generally not definitive.
Track Number/Description
1. Territorial scream or advertising call.
A male probably produced this call, described
as karr-r-r-r-r-ick. (California, Geoffrey A.
Keller, ML 50147)
2. Territorial scream or advertising call.
Described as shrrreeeeee, this call was probably
made by a female. (Washington, David S.
Herr, ML 50540)
3. Territorial screams and wing-clap display.
The first scream is probably by a male, the
second by a female. (New York, Charles A.
Sutherland, ML 8323)
6
4. Warning scream, or alarm call of an adult.
(Washington, David S. Herr, ML 50541)
5. Distress call of a captive owl. This call
indicates intense distress or fear such as when
an owl has been seized or is in an intense
fight. (New York, Martin C. Michener, ML
8320)
6. Sustained defensive hiss, bill-clap, and
warning scream by captive advanced nestlings.
(New York, Sally Spofford, ML 8325)
7. Sustained defensive hiss by an adult. Owls
often use this call when threatened or cornered,
often accompanied by threat postures.
If the danger persists, this call often grades
into the distress call. These calls and the related
postures are intended to intimidate predators.
Captive. (New York, Peter Paul Kellogg,
ML 8319)
8. Kleak-kleak call. The male commonly utters
this call in flight during nesting, often to
announce food deliveries to the nest.
(California, Robert C. Stein, ML 8322)
9. Calls recorded at a nest. The behavioral
context for this recording is unknown but
calls suggesting the food-offering call and
adult begging snore are heard in this recording.
A male may have been delivering food to
an incubating female. (California, William R.
Fish, ML 22812)
10. Fledgling mobbing call.
Owls usually direct this scolding
call toward terrestrial predators,
including humans. A
second fledgling is audible, uttering
begging snores. (Florida,
Gerrit Vyn, ML 104569)
11. Fledgling begging snore.
Juvenile and female owls
use this self-advertising call.
The calls’ intensity increases
with hunger and the arrival
of adults with food. Hungry
fledglings will give this call
persistently throughout the
night. (Florida, Gerrit Vyn,
ML 104569)
DISC 1
Juan Bahamon

Flammulated Owl Otus flammeolus
Although the Flammulated Owl is one or our
smallest owls, its hoot is one of the lowestfrequency
owl songs in North America. The
male’s hoot also has a ventriloquial quality,
making it difficult to observe this small, cryptically
colored, nocturnal owl. The owls also
vary the amplitude of their hoots, making it
difficult to judge the distance to a calling owl.
The vocalizations of adult Flammulated Owls
consist of one basic note type which grades
from short hoots to long shrieks, with many
variations in between. These varied intermediate
calls are commonly described as barks
and moans.
12. Male territorial hoot or advertising song.
Males primarily give the single-note hoot
when singing. When a male is agitated, such
as when another male invades a territory,
the hoot may be accompanied by additional
notes, or may become more quiet, hoarse,
and with multiple notes, as is heard in the
last call here. (Oregon, David S. Herr, ML
47540)
13. Female hoot. A female uttered these
hoots as she solicited courtship feedings
from a male. (New Mexico, D. Archibald
McCallum, 5/12/81)
7
14. Begging snores of nestlings and low amplitude
hoot given by an adult announcing
a food delivery to the nest. Adults also use
low amplitude hoots as a contact call between
mates. (Oregon, David S. Herr, ML 50536)
15. Bark by an alarmed female, and nestling
begging snore. Barking can escalate into a variety
of screams and shrieks depending on an
owl’s level of agitation or aggression. (Oregon,
David S. Herr, ML 50536)
16. Male bark in response to a human
intruder near a pair. (New Mexico, D.
Archibald McCallum, 4/29/03)
17. Female moan. (New Mexico, D.
Archibald McCallum, 7/6/83)
18. Distress shriek and bill-clap of an injured
bird. (Texas, Greg Lasley, FMNH 1288)
DISC 1
Brian E. Small

Western Screech-Owl Megascops kennicotti
Like other North American screech-owls, the
Western Screech-Owl uses two song types.
The bouncing ball song is used for territorial
advertisement and defense. The double trill is
a mate coordination song and is heard more
frequently in pair duetting. Males sing most
often in winter and early spring prior to egglaying.
They often sing from potential nest
cavities or nest trees. Singing increases again
in late summer as young disperse from adult
territories. Both sexes share the adult vocalizations,
with the female having a noticeably
higher voice.
19. Pair duet. Bouncing ball and double trill
songs are given by both sexes. The female’s
voice is higher pitched. Various unidentified
calls are audible during an interaction
between a pair at the end of the recording. Elf
Owl (Micrathene whitneyi) barks are also audible
during the duet. (Arizona, Geoffrey A.
Keller, ML 109017)
20. Double trill song followed by bouncing
ball song. Mates use the double trill as
a contact call. The male also uses the double
trill to announce food deliveries to the nest.
(Washington, David S. Herr, ML 47692)
21. Agitated bark and bill-clap. (Washington,
David S. Herr, ML 63001)
8
22. Te-te-do call progressing into agitated
double trill. This call requires further study
but is known to be given by owls when confronted
by others of the same species. It may
be an intense proclamation of territory and
is often combined with the double trill. It is
also similar to the solicitation or begging call
of females and juveniles. (Oregon, David S.
Herr, ML 50549)
23. Female solicitation call or begging whinny.
The female uses this call to solicit feedings
and copulation in the early stages of nesting
and when incubating and brooding young.
It is derived from the juvenile begging call.
(Alaska, Kent and Meredith Bovee, 4/29/05)
DISC 1
Robert McMorran

Eastern Screech-Owl Megascops asio
The Eastern Screech-Owl uses its descending
trill song, or whinny, mainly for territorial
advertisement or defense. Adults most
commonly use this song from the time when
fledglings disperse in late summer until
courtship begins again in mid-winter. The
monotonic trill song establishes pair and family
bonds and is primarily used during the
courtship and pre-nesting period from midwinter
through spring. The owls also produce
variations of this song during copulation and
nest-cavity advertising. Additionally, the male
uses the song prior to food deliveries and the
female uses it to induce fledging. Pair duets
are common and neighboring males will also
synchronize their singing. Considerable variation
in both song types between individuals
may serve in sexual and individual recognition.
Both sexes utter all vocalizations, with
the male’s voice noticeably lower.
24. Descending trill or whinny, followed by
the monotonic trill. The monotonic trill is
a variable vocalization that sometimes has a
bouncing quality as is heard in this example.
At other times it is a more consistently delivered
song. Captive. (New York, Hugh P.
McIsaac, ML 20427)
9
25. Descending trill during territorial defense.
(Maryland, Wilbur L. Hershberger,
ML 100704)
26. Monotonic trill with descending trill
in the background. (Maryland, Wilbur L.
Hershberger, ML 107446)
27. Monotonic trill with evenly spaced notes.
Chuck-will’s-widow (Caprimulgus carolinensis)
is prominently audible in the background.
(Florida, Geoffrey A. Keller, ML 105733)
28. Monotonic trill of shorter duration
by M.a. mccallii in South Texas. (Texas,
Matthew D. Medler, ML 87462)
29. Screech calls and bill-claps by agitated
pair. (Maryland, Wilbur L. Hershberger, ML
94524)
30. Screech and chuckle rattle. Both nestlings
and adults utter the chuckle rattle, generally
signifying annoyance. Captive. (New York,
Hugh P. McIsaac, ML 20428)
31. Bark call. Captive. (New York, Hugh P.
McIsaac, ML 20428)
32. Begging rasps, chitter calls, and chuckle
rattle of nestlings. (New York, Arthur A.
Allen, ML 4451, 4452, 4451, 39893)
33. Food delivery at a nest. (New York,
Arthur A. Allen, ML 39890)
DISC 1
Gerrit Vyn

Whiskered Screech-Owl Otus trichopsis
The Whiskered Screech-Owl uses its short
trill as a song for territorial proclamation
and defense, as well as for pair bonding and
contact. The telegraphic trill is a variable syncopated
song often sung in duet by pairs. It
is associated with pair contact, defense of territory,
and copulation. Both sexes sing, with
the female having a noticeably higher voice.
Most singing occurs at night with peaks in
singing at dusk and before sunrise. Like Elf
Owls and other screech-owls, Whiskered
Screech-Owls sing most frequently during
gibbous to full moons on clear nights.
34. Male short trill. The male uses this song
in territorial defense and when advertising
prospective nest cavities. (New Mexico,
Curtis A. Marantz, ML 112621)
35. Male short trill. (Arizona, Geoffrey A.
Keller, ML 40588)
36. Telegraphic trill of male. (Arizona, Greg
Clark, 1/97)
37. Telegraphic trill by a pair followed by a
squeal during an encounter with an invading
owl. Pairs also use this song in response to
small singing owls of other species. (Arizona,
Bernard Lohr, 5/31/99)
10
38. Male prolonged or long trill. This song
is only known to be given by the male in the
immediate vicinity of the nest cavity. It may
signal intense territoriality. When a female
is present, the call may become deeper and
more guttural (not heard here). (Arizona,
Bernard Lohr, 5/30/99)
39. Hoot. This call may be a warning in response
to the presence of potential predators.
(Arizona, Greg Clark and Tim Price, 1/97)
40. Male whistle call. Used by both sexes in
mate contact, this call often precedes copulation.
(Arizona, Frederick R. Gehlbach,
6/21/98)
41. Bark series. This was one of three series of
bark-like calls by a male near a nest. (Arizona,
Bernard Lohr, 5/30/99)
42. Female bark call transitioning into
screech. Owls often direct barks at intruders
near the nest. The barks may escalate
into screeches as an owl’s level of agitation
or aggression increases. (Arizona, Joseph T.
Marshall Jr., ML 4506)
43. Copulation sequence. The female whistle–calls
prior to copulation, followed by the
telegraphic trill from both sexes. Both sexes
utter other calls during copulation. (Arizona,
Frederick R. Gehlbach)
DISC 1
Brian E. Small

Great Horned Owl Bubo virginianus
Although the Great Horned Owl is our most
widespread and recognized owl species, its
wide repertoire of calls is little known and
poorly understood. In addition to the familiar
territorial hooting, Great Horned Owls utter
a variety of barks, growls, screams, and chuckles
that are difficult to characterize. Pair duets
can be heard throughout North America at
any time of the year but most frequently in
late winter and early spring prior to egg laying.
Males can always be distinguished from
females by their deeper, more mellow voice.
Considerable variation exists in the timing
and number of hoots in a song. The fledgling
begging call is another commonly heard
call in the field that observers often do not
recognize. It can be heard from late spring
through fall.
44. Territorial hooting or advertisement
song. Often sung in duet, this call announces
a territory and may serve to strengthen the
pair bond. It is heard most commonly prior
to egg-laying, often in the immediate vicinity
of a chosen nest. When giving this hoot in
song, the owl assumes a forward leaning posture
with a cocked tail and an inflated throat.
The number and timing of hoots varies
among different individuals and populations.
A double-hoot by the female is also audible.
11
This is probably the result of an interruption,
rather than being a unique vocalization.
(California, William R. Fish, ML 22874)
45. Territorial hooting duet followed by
copulation calls. Both birds, particularly the
male, can be heard giving repeated hoots during
copulation, followed by a squealing chitter
call by the female. The interaction ends
with a resumption of the duet. (New York,
Gerrit Vyn, ML 128900)
46. Female squawk with male territorial
hoot in the distance. The squawk is a variable
call sometimes used as a food solicitation call
by the female early in the breeding season.
The male also uses it. It is probably derived
from the juvenile begging call. (Connecticut,
Sean O’Brien)
47. Female chitter call and squawk and male
territorial hooting. (Maryland, Wilbur L.
Hershberger, ML 94364)
48. Male territorial hooting, female territorial
hooting and squawks. (Arizona, Charles
M. Bogert, ML 8366)
49. Bark-like call. This may be a single wac
call as heard on the following track. Captive.
(Pennsylvania, Peter Paul Kellogg, ML 8359)
50. Wac-wac call and billclap
by a female during nest
defense. Male hooting, which
may functionally be a nestdefense
or alarm call in this
context, is audible in the background.
(Manitoba, William
W. H. Gunn, ML 59821)
51. Squealing chitter call of
an injured bird. This call varies
in intensity and generally expresses
discomfort or agitation.
Adults and juveniles use it in a
variety of contexts. (New York,
Peter Paul Kellogg, ML 8360)
52. Fledgling begging
call. (New York, David T.
Spaulding, ML 8380)
DISC 1
Gerrit Vyn

Snowy Owl Bubo scandiaca
During the breeding season, Snowy Owls
are vocally active and use a wide repertoire of
vocalizations. This is especially true of males,
who are more responsible for the defense of
territory and nest than are females. Little information
is available on the vocal activity of this
species outside of the nesting season, though it
is clear they call infrequently. They are known
to give several calls on their wintering grounds,
particularly when defending winter feeding
territories from other Snowy Owls. One call,
often described as a scream, is probably a variation
of the mewing whistle. It is given by both
sexes and often by owls that are approached
too closely by observers.
53. Male territorial hoot or advertising song.
Usually uttered in twos, variations of this
vocalization probably serve as both song and
call at times. When advertising a territory,
males assume a forward bowing posture
when giving this call. They also occasionally
utter it in flight. Hooting volume is loudest
during territorial defense. Females are known
to hoot but rarely do so. (Sweden, Sture
Palmer, ML 9435)
54. Female bark call and bill snap. This alarm call
is the most common call heard by human intruders
at the nest. The piping squeals of small chicks
12
are also audible in this recording. (Nunavut,
Canada, Stewart D. MacDonald, CMN)
55. Male bark call given in alarm at a nest.
The begging squeals of chicks are also audible.
(Nunavut, Canada, Stewart D. MacDonald)
56. Mewing whistle of female. Primarily given
by the female, this call is used in a variety of
situations, most commonly when soliciting food
from the male at the nest. She also uses this call
before and after being fed by the male, during
distraction display, and in displacement coition.
This call is also given in alarm when humans
are near a nest. (Nunavut, Canada, Stewart D.
MacDonald, CMN)
57. Unidentified call. (Sweden, Sture Palmer,
ML 9435)
58. Unidentified call. (Sweden, Sture Palmer,
ML 9434)
59. Begging squeal and chitter call of fiveday-old
chick. (Nunavut, Canada, Stewart D.
MacDonald, CMN)
60. Fledgling begging call and chitter. Young
Snowy Owls leave the nest at an early age and
disperse across the tundra around the nest. This
call serves as a begging call and self-advertisement
so adults can locate them for feeding.
(Sweden, Sture Palmer, ML 9435)
DISC 1
Gerrit Vyn

Spotted Owl (“Northern” subspecies) Strix occidentalis caurina
Because of its status as an endangered species,
the Spotted Owl has been studied more than
any other North American owl. Vocally active,
it commonly calls during the day if provoked to
defend its territory. Otherwise, it is most vocal
after sunset, early evening, and dawn. The sexes
can usually be distinguished by voice pitch; the
female’s vocalizations are higher. Both sexes use
most vocalizations, but some of them are used
more regularly by one sex. Most Spotted Owl
hooting and contact vocalizations are used and
intermixed during territorial encounters. These
calls can vary significantly depending on the
individual and circumstances. Playing recordings
in the field of this federally protected endangered
species is strongly discouraged.
61. Male advertisement hooting or four-note
location call. This is the most common hooting
call. The male uses this primary song to
announce a territory or when engaging in territorial
disputes. Members of a pair also use it
as a location call. A female contact whistle is
audible in the background. (Oregon, Thomas
G. Sander, ML 125367)
62. Female advertisement hooting or fournote
location call. (Oregon, Thomas G.
Sander, ML 125377)
63. Variation of four-note location call by a
female. Owls commonly produce a three-note
13
location call when agitated. (Oregon, Geoffrey
A. Keller, ML 56948)
64. Variation of four-note location call by
a male. In this example, the owl adds a note
to the end of the call. (Oregon, Geoffrey A.
Keller, ML 56949)
65. Male series location call with female
contact whistle in the background. This variable
call consists of a series of hoots often ending
with hoots similar to those ending the fournote
location call. Males commonly use this
call in territorial disputes but pairs also use it
as a contact call. (Oregon, Thomas G. Sander,
ML 125369)
66. Female series location call consisting
of a series of evenly spaced notes. (Oregon,
Thomas G. Sander, ML 125377)
67. Female series location call ending with an
agitated contact whistle. (Oregon, Thomas G.
Sander, ML 125375)
68. Male series location call followed by female
contact whistle. (Oregon, Geoffrey A.
Keller, ML 56948)
69. Contact whistle. This call is commonly
heard and can vary greatly in intensity. Used
more often by the female, this call advertises
her location to her mate and offspring.
(Oregon, Thomas G. Sander, ML 125361)
70. Female agitated contact whistle of varying
intensities. (Oregon, Thomas G. Sander, ML
125374)
71. Female bark series. This variable call is primarily
used by the female during high intensity
territorial disputes. It is also used as a general contact
call in some instances. (Oregon, Thomas G.
Sander, ML 125373)
72. Mellow female contact whistle and male nest
call. The male uses the nest call when advertising
potential nest sites to the female in the pre-nesting
period, often calling continuously for several minutes.
(California, Arthur A. Allen, ML 4544)
73. Interaction between mates. A male utters a
contact whistle in flight as he approaches a female,
possibly delivering food. The female responds with
a chitter call, followed by an agitated location call
while the male begins giving the typical four-note
location call. The female continues with whistle
contact calls. The agitated location call is similar
to the four-note location call but ends with an
excited OW!. It is frequently heard when birds are
excited during territorial encounters, sexual encounters,
or food exchanges. (Oregon, Geoffrey A.
Keller, ML 56948)
74. Interaction by members of a pair. The male
utters the series location call as the female flies
in, giving contact whistles and chitter calls as she
arrives. She then gives typical four-note location
DISC 1
calls as the male departs, issuing agitated
location calls. The female may have been
soliciting a food transfer from the male.
The chitter call is used during food transfers,
copulation, and allopreening. It is also
known to be used to express discomfort.
(Oregon, Thomas G. Sander, ML 125368)
Gerrit Vyn

Spotted Owl (“Mexican” subspecies) Strix occidentalis lucida
The vocal behavior of the “Mexican”
Spotted Owl is generally the same as that
of the “Northern” Spotted Owl, though the
Mexican subspecies is less inclined to vocalize
during the day. Further descriptions and
behavioral contexts of these calls can be found
in the previous section about the northern
subspecies. Playing recordings in the field of
this federally protected endangered species is
strongly discouraged.
75. Male advertisement hooting or four-note
location call. (New Mexico, Wendy Kuntz,
3/14/95)
76. Male advertisement hooting or four-note
location call. (New Mexico, Wendy Kuntz,
6/19/96)
77. Female advertisement hooting or fournote
location call. A male is also audible in
the background. (Arizona, Virginia Huber,
ML 20869)
78. Female agitated location call, male
four-note location call, and female agitated
contact whistle. The agitated location call is
similar to the four-note but ends in an excited
OW!. (Arizona, Virginia Huber, ML 20869)
79. Female and male agitated location calls.
In this example, the higher-pitched female
14
has omitted the first note. (New Mexico,
Wendy Kuntz, 6/10/96)
80. Male series location call with unevenly
spaced notes. (New Mexico, Wendy Kuntz,
7/16/96)
81. Male series location call with evenly
spaced notes. (New Mexico, Wendy Kuntz,
4/5/96)
82. Whistle contact calls of variable intensity
by male and female. (New Mexico, Wendy
Kuntz, 6/10/96)
83. Agitated contact whistles by a pair. (New
Mexico, Wendy Kuntz, 6/10/96)
84. Bark series by male and female. The
song of Canyon Wren (Catherpes mexicanus)
is audible in the background. (New Mexico,
Wendy Kuntz, 8/3/96)
85. Various cooing calls between pair.
Cooing calls are variable soft calls often used
when members of a pair are in close association,
such as when roosting together or
allopreening. (New Mexico, Wendy Kuntz,
8/1/96)
86. Variable contact-like calls and barks.
(Arizona, Virginia Huber, ML 20870)
87. Copulation sequence. (Arizona, Virginia
Huber, ML 20869)
88. Male prey delivery to female. Male gives
four-note location call and agitated location
call; female responds with chitter, squeals,
and contact-like calls. (New Mexico, Wendy
Kuntz, 5/7/96)
89. Fledgling begging call. This call gradually
develops into the adult contact call. (New
Mexico, Wendy Kuntz, 6/23/96)
Spotted Owl x Barred Owl hybrid
Strix occidentalis x varia
Unsustainable forestry practices in the Pacific
Northwest have not only eliminated most of
the Spotted Owl’s old-growth forest habitat,
but they have created corridors of younger
forest habitat that the more adaptable Barred
Owl has readily occupied. The fragmentation
of Spotted Owl habitat and subsequent invasion
of the Barred Owl into adjacent territory
has put the Spotted Owl at great risk of being
displaced by the more aggressive and closely
related Barred Owl or of breeding with it. In
many cases the two species have hybridized,
producing viable offspring, which further
threaten the survival of the Spotted Owl, an
endangered species.
90. Advertisement hooting. (Washington,
J. R. Fletcher, ML 93740)
DISC 1

Barred Owl Strix varia
The Barred Owl is one of the most spectacular
vocal performers of any North American
bird. Its familiar who cooks for you, who cooks
for you all territorial announcement song, or
two-phrase hoot, can be heard in many parts
of the continent. Female calls can usually be
distinguished from those of males by their
higher pitch and more tremulous trailing
notes. Pairs defending or announcing a territory
frequently caterwaul, producing a variety
of spectacular hoots, squeals, and quacks.
These caterwauling bouts are strictly performed
by mated pairs, usually to announce
or defend a territory against other Barred
Owls. The ascending hoot is another territorial
hooting variation commonly heard when
one pair confronts another. Barred Owls
are one of the few owl species that are commonly
heard throughout the day in many
parts of their range, particularly in southern
swamplands where breeding densities are the
highest.
91. Female two-phrase hoot, ascending hoot,
and pair caterwauling. (South Carolina,
Geoffrey A. Keller, ML 105433)
92. Pair caterwauling. (Florida, William R.
Evans, ML 49708)
93. Pair caterwauling with nestling begging
15
call in background. (Arkansas, Gerrit Vyn
and Benjamin M. Clock, ML 128923)
94. Female two-phrase hoot, followed by
male ascending hoot, and a female ascending
hoot variation. This variation is similar to
that heard being given by an owl in flight on
Disc 2 Track 99. (Arkansas, Gerrit Vyn and
Benjamin M. Clock, ML 128930)
95. Territorial dispute between two pairs. The
proximate pair gives ascending hoots. Female
two-phrase hoots and caterwauling are audible
from a neighboring pair. (Arkansas, Gerrit Vyn
and Benjamin M. Clock, ML 128925)
96. Territorial dispute between two pairs.
Ascending hoots, caterwauling, and a booming
hoo-aw call are audible. (Arkansas, Gerrit
Vyn and Benjamin Clock, ML 128926)
97. Male hoo-aw call. This call may be used
as a long distance contact call between mates.
(Arkansas, Gerrit Vyn, ML 128927)
98. Female hoo-aw call. Mates may use this
call as a long distance contact call. (New York,
Randolph S. Little, ML 106944)
99. Female hoot variation. Females have been
observed giving this call in flight while chasing
other Barred Owls invading their territory.
(Arkansas, Gerrit Vyn, ML 128931)
DISC 1 / DISC 2
DISC 2
Barred Owl Strix varia
continued
1. Female solicitation call from
nest cavity. When incubating
eggs or brooding young
chicks, females may utter this
call repeatedly throughout the
night as a food begging call
to their mates. This call is also
used as a contact call in some
circumstances. (Arkansas,
Gerrit Vyn, ML 128902)
2. Distraction squeals and honk
by a female in response to a large
predator near the nest. This call
is possibly being used in an
injury-feigning display. (Arkansas,
Gerrit Vyn and Benjamin M.
Clock, ML 128924)
3. Fledgling begging call. (Florida,
Robert C. Stein, ML 4549)
4. Fledgling begging call and
male two-phrase hoot.
(Maryland, Wilbur L.
Hershberger, ML 79462) Gerrit Vyn

Great Gray Owl Strix nebulosa
The Great Gray Owl has a large vocal repertoire
during the breeding season. Both sexes use
many of the same calls. Calls associated with
defense of the nest and contact between pairs
and juveniles are especially diverse and variable.
Territorial hooting is most often heard during
late winter and spring, but is also heard at
other times of the year. The juvenile begging
call is also frequently heard. It often sounds
similar to that of the Great Horned Owl.
5. Male territorial hooting. This call is primarily
given by the male to promote pair
formation, establish territory around a nest
site, and in nest-showing. The female uncommonly
gives a higher-pitched, harsher version
with fewer notes, prior to egg laying. Captive.
(Alaska, Leonard J. Peyton, ML 49945)
6. Defensive or warning hooting. This call
serves as a contact call between members of a
breeding pair, often when intruders are near
a nest site. It is sometimes given by the male
when the female is off the nest. (Oregon,
David S. Herr, ML 48904)
7. Defensive or warning hooting of an aggressive,
highly agitated female. This call is of a
greater intensity than the previous call and directed
towards a threat to the nest. It is given by
both sexes. (Oregon, David S. Herr, ML 48904)
16
8. Male contact hoots announcing a prey delivery
to the nest. A female g-wuk call is also
audible. (Minnesota, Lang Elliott, 6/14/93)
9. Female contact call or whoop. The most
common call given by the female, this vocalization
is used for mate and family contact
and as a food solicitation call from the nest.
A red squirrel (Tamiasciurus hudsonicus)
is also audible in this recording. (Oregon,
David S. Herr, ML 47532)
10. Female contact call or g-wuk. A variation
of the call on Disc 2, Track 9. This female
was soliciting food while in a nest. This call
can vary greatly in intensity. Nestling begging
calls are also audible. (Minnesota, Lang
Elliott, 6/14/93)
11. Chitter call of adult. This call is used in a
variety of circumstances, most often by adults
and juveniles during food transfers. It is also
used to express discomfort, hunger, annoyance,
and concern. Captive. (Alaska, Leonard
J. Peyton, ML 49941)
12. Distraction calls. A female uttered
these calls during a distraction or injuryfeigning
display near a nest. (Manitoba,
Lang Elliott, 6/1/93)
13. Agitated call by a female after a distraction
display. (Manitoba, Lang Elliott, 6/1/93)
14. Fledgling begging call interspersed by
two exclamatory hoots that were probably
given by the female. The owl uttered these
hoots after it approached a vocalizing pine
marten (Martes americana) which can be
heard giving perturbed growls. Red squirrel
(Tamiasciurus hudsonicus) is also audible.
(Wyoming, Gregory F. Budney, ML 62945)
15. Food exchange at nest site. First, a female
utters the g-wuk food solicitation call and
nestlings use chitter calls. A male flies in to
a nearby tree, giving contact calls while the
nestlings begin giving begging calls. As the
male flies closer the intensity of the female’s
g-wuk calls increases until she flies from the
nest to receive prey from the male. At the
time of food transfer, the male utters chitter
calls and three deep hoots. The female returns
to the nest. She and the nestlings utter chitter
calls as food is transferred. The female also
gives several softer squeals at the nest and
during her return flight. (Minnesota, Lang
Elliott, 6/14/93)
16. Fledgling begging call. The howling of
coyote (Canis latrans) is also audible.
(Wyoming, Gregory F. Budney, ML 62947)
DISC 2
Gerrit Vyn

Northern Hawk Owl Surnia ulula
A diurnal-crepuscular owl of the northern
boreal forest, the Northern Hawk Owl is
vocal and conspicuous during the breeding
season. During that time, males sing from
prominent perches within their territories,
primarily around dawn and dusk. In a variety
of contexts, both sexes utter various trilling
calls that are similar to the male’s primary
song. This species also has a wide repertoire of
alarm calls used around the nest. During the
nonbreeding season, Northern Hawk Owls
are relatively quiet but do use several of the
vocalizations described below.
17. Male advertising song. This song may
last up to 14 seconds and is often uttered in a
display fight over the territory. The male also
uses this song to advertise potential nest sites
to the female. (Alaska, Leonard J. Peyton, ML
49544)
18. Trilling call. Both sexes use various trilling
calls that are difficult to characterize. They
use these calls in many contexts, including
during nest disturbances. The male and
female also utter trilling calls in duet during
prey exchanges and copulation. (Alaska,
Leonard J. Peyton, ML 49902)
19. Screeching call or screeee-yip followed
by yelping call. Both sexes commonly issue
17
these calls in alarm when an intruder is near a
nest. They also use the screeching call widely
in other contexts, including mate contact,
food delivery, and female food solicitation.
The yelping call is often uttered in flight, including
during aerial attacks of potential nest
predators. Nestling begging calls, similar to
the adult screeching call, are audible in the
background. (Alaska, Leonard J. Peyton, ML
49954)
20. Alarm squeals. An agitated owl near a
nest uttered this call. It may be a distraction
call. (Alaska, Leonard J. Peyton, ML 49910)
21. Distress call. In winter, observers somtimes
hear low-intensity versions of this call,
given by alarmed owls. Captive. (Ontario,
William W. H. Gunn, ML 61801)
DISC 2
Gerrit Vyn

Northern Pygmy-Owl Glaucidium gnoma
Heard throughout much of the coastal and
mountain West, the diurnal-crepuscular
Northern Pygmy-Owl sings most frequently
near sunrise and sunset. It is also known to
sing during the day. Songs of this species vary
geographically and suggest that this species
may be designated as several species in the
future.
[Note: The “chitter” calls described for
Northern and Ferruginous pygmy-owls are
not analogous to the chitter calls of other
owl species. The use of the term “chitter” to
describe pygmy-owl vocalizations may be the
more appropriate usage. The term “discomfort
call” may be more appropriate for describing
the “chitter” in other owl species.]
22. G.g. grinnelli. Male primary advertising
or toot song. This is the common single-note
song of the western coastal subspecies G.g.
grinnelli. The primary song is often preceded
by a trill which is not heard here. (Oregon,
Geoffrey A. Keller, ML 105504)
23. G.g. californicum. Male primary advertising
or toot song. This is the common
single-note song of the subspecies G.g. californicum.
Found throughout much of the
interior West, this subspecies is also known
18
to give a double-note song (not heard here).
(Montana, Robert C. Faucett, ML 25653)
24. G.g. gnoma. Male primary advertising or
toot song. The subspecies G.g. gnoma, found
in southeast Arizona and Mexico, typically
sings a double-note song but will also sing a
fast single-note song as heard here. (Arizona,
Geoffrey A. Keller, ML 40576)
25. G.g. gnoma. Male primary advertising or
toot song. This is the typical double-note song
of subspecies G.g. gnoma, or “Mountain
Pygmy-Owl,” found in southeast Arizona and
Mexico. (Arizona, L. Irby Davis, ML 9418)
26. Male primary advertising song interspersed
with prolonged chitter call. Soft
female chitter calls can be heard which initiate
the male’s use of the prolonged chitter.
The behavioral context for this recording
is unknown, although it seems to indicate
a level of sexual excitement. It is probably
analogous to the Ferruginous Pygmy-
Owl sequence heard on Disc 2, Track 34.
(Arizona, Frederick R. Gehlbach, 4/2/00)
27. Female chitter call. (Arizona, Frederick
R. Gehlbach, 4/2/00)
28. Copulation calls. (Colorado, Robert
Righter, 6/97)
29. Food delivery at a nest.
In this sequence the male
gives several toots to announce
a delivery. The female
comes out of the nest,
uttering chitter calls. She
receives the food and returns
to the nest cavity. (Arizona,
Frederick R. Gehlbach, 2000)
30. Female chitter call followed
by an unknown call.
The voice of a researcher is
briefly heard at the end of this
recording. (Arizona, Bernard
Lohr, 6/6/00)
31. Fledgling begging call.
(Washington, Charles A.
Sutherland, ML 9419)
DISC 2
Jared Hobbs

Ferruginous Pygmy-Owl Glaucidium brasilianum
A diurnal-crepuscular owl of extreme southern
Arizona and Texas, the Ferruginous
Pygmy-Owl is a common bird south of the
border. It sings most frequently near dawn
and dusk but also during the day and occasionally
at night. Its song varies widely in
volume, frequency, and duration. Both males
and females use a version of the primary advertising
song, with the females’ voices higher
and sweeter. Researchers have proposed that
this species should be split into two species,
with the birds occurring in the United States
referred to as Ridgway’s Pygmy-Owl
(Glaucidium ridgwayi).
32. Male primary advertising or territorial
song. (Texas, Geoffrey A. Keller, ML 105563)
33. Female primary advertising or territorial
song. (Arizona, Greg Clark and Tim Price,
2/02)
34. Male primary advertising song interspersed
with prolonged chitter calls. The
female utters soft chitter calls that seem to
initiate the male’s use of the prolonged chitter.
The behavioral context for this recording
is unknown, although it seems to indicate
sexual excitement. It is probably analogous
to the Northern Pygmy-Owl sequence on
19
Disc 2, Track 25. (Mexico, Andres M. Sada,
FMNH 1019)
35. Female chitter call. The female uses this
vocalization as a food solicitation call. She
uses a shortened chitter as a contact call. It
is derived from the fledgling begging call.
(Texas, Glenn A. Proudfoot, 6/99)
36. Female alarm or pee-weeet call. Females
often use this call when human intruders are
near the nest. (Texas, Glenn A. Proudfoot,
6/99)
37. Female aggression call. The owls utter
this call in mild agitation when intruders
approach the nest and in response to other
Ferruginous Pygmy-Owl songs near the nest
site. This call is commonly given by females,
less often by males. (Texas, Glenn A.
Proudfoot, 4/98)
38. Female aggression call. (Arizona, Greg
Clark and Tim Price, 2/02)
39. Nestling distress call. (Texas, Glenn A.
Proudfoot)
40. Fledgling begging chitter. The calls of
Western Tanager (Piranga ludoviciana) are
also prominent. (Texas, Glenn A. Proudfoot)
DISC 2
Gerrit Vyn

Elf Owl Micrathene whitneyi
North America’s smallest owl, this species
is a common spring singer in parts of the
Southwest. Although they are often associated
with giant saguaro cacti, Elf Owl can be
heard wherever suitable woodpecker cavities
can be found for nesting. This includes many
areas familiar to birders in southeast Arizona,
where riparian sycamores and cottonwoods
provide nest sites.
41. Male chatter song and female station
call. The male uses the chatter song for territorial
advertisement and defense as well as to
attract a mate. It is most often heard at dusk
and dawn during the period of nest-site selection
and pair formation in April and May.
Both sexes use the station call as a contact call
between mates and young. (Arizona, Geoffrey
A. Keller, ML 40636)
42. Prolonged male chatter song and female
calls. Males utter this song from within a potential
nest cavity or its immediate vicinity to
lure the female to the cavity. Its intensity increases
as the female responds or approaches.
Various female calls can also be heard, including
a cricket-like twitter in flight. (Arizona,
Bernard Lohr, 5/7/01)
43. Bark call and station call given by pair.
The bark call is an alarm call or scolding call
20
directed at intruders, including humans, near
the nest site. Used by both sexes, it varies in
intensity depending on the owl’s level of agitation
or alarm. A second bird can be heard
giving the station call midway through the
recording. (Arizona, Bernard Lohr, 6/6/00)
44. Bark call. (Arizona, William W. H.
Gunn, ML 59816)
45. Copulation calls. (Arizona, J. David
Ligon, ML 42361)
46. Nestling begging rasp. (Arizona,
Harriette Barker, ML 25169)
DISC 2
Brian E. Small

Burrowing Owl Athene cunicularia
Considered an accomplished vocalist, the
Burrowing Owl is known to have a large repertoire
of calls beyond those presented here.
Its calls are well known, partly because of its
diurnal activities and open country habitat,
which have provided researchers with good
opportunities for direct observation of vocalizing
birds. Burrowing Owls are most active
vocally in the spring, though courtship and
alarm calls can be heard throughout the year.
47. Male primary or courtship song. The
male uses this song in the vicinity of the nest
burrow. This territorial or advertisement song
is accompanied by the bowing display.
(California, Geoffrey A. Keller, ML 119481)
48. Alarm chatter. Burrowing Owls use this
call in nest defense or predator mobbing. It
varies in intensity and duration. (California,
Geoffrey A. Keller, ML 118856)
49. Single alarm notes and alarm chatter.
(Alberta, Albert Karvonen, ML 59807)
50. Alarm chatter at burrow. (California,
Gregory F. Budney, ML 126498)
51. Nestling begging rasp and adult alarm
chatter at burrow. (California, Gregory F.
Budney, ML 126498)
21
52. Juvenile alarm call or rattlesnake rasp.
When highly distressed, young owls utter
this call from the nest burrow. It is believed
to mimic the rattle of a rattlesnake (Crotalis
spp.) to deter potential predators. Threatened
adults sometimes produce a more convincing
version. (Idaho, Jeffrey Rice, 6/22/04)
DISC 2
Gerrit Vyn

Boreal Owl Aegolius funereus
In recent years, the detection of singing and
calling Boreal Owls has led to the discovery
that Boreal Owls breed in many subalpine
areas of the West as far south as New Mexico.
Previously they were thought to breed only in
the boreal forests. The male’s song is primarily
heard in late winter and early spring prior
to egg-laying. Unpaired males may continue
singing into summer. Some of the Boreal
Owl’s calls are very similar to those of the
Northern Saw-whet Owl.
53. Male primary or staccato song. This song
serves as a long distance advertisement to
potential mates and is usually given in the
vicinity of potential nest cavities. Some listeners
have confused this song with the winnowing of
Wilson’s Snipe (Gallinago delicata). (Alaska,
Leonard J. Peyton, ML 49540)
54. Male prolonged staccato song. The male
uses this song to advertise a nest cavity when the
female is present. The male may fly to and from
a potential nest cavity and the female, giving
the prolonged song in flight and from the cavity
itself. Males often switch from the primary song
to the prolonged song when the female appears.
The song, which facilitates pair formation, is delivered
softly compared with the primary song.
(Minnesota, Steven G. Wilson, 6/89)
22
55. Male subdued staccato song or brief
trill. Males utter a subdued version of the
primary song in many instances. It is often
heard prior to, after, or between long bouts of
the primary song. It is also sometimes used as
the initial vocalization during a food delivery.
(Minnesota, Steven G. Wilson, 6/89)
56. Skiew call or screech. Both sexes use this
variable call in a wide variety of contexts.
Often delivered quite loudly, it commonly
ends in a bill-clap. It is used year round and
is often heard in response to broadcast of the
primary song. It may serve as a contact call or
a warning call, or it may suggest annoyance.
(Minnesota, Steven G. Wilson, 6/89)
57. Food delivery or moo-a call. The male
uses this variable call to announce food deliveries
to the nest or fledglings. Calls similar
to this are also heard in response to broadcast
of the primary song. (Minnesota, Steven G.
Wilson, 6/89)
58. Nestling peep and male food delivery
call. (Minnesota, Steven G. Wilson, 6/89)
59. Nestling chatter and female peep call
from the nest. The female uses the peep call
widely during the breeding season when soliciting
food from the male or as a contact call.
This call is derived from the juvenile begging
call. (Alaska, Rosa Meehan,
BLB 22369)
60. Fledgling begging call
or peep, male food delivery
call, and a soft skiew call.
The winnowing of Wilson’s
Snipe (Gallinago delicata)
is also audible. (Minnesota,
Steven G. Wilson, 6/89)
DISC 2
Gerrit Vyn

Northern Saw-whet Owl Aegolius acadicus
The diminutive Northern Saw-whet Owl is
most conspicuous during the brief period from
February through April when most male singing
occurs. Throughout the rest of the year this
species is heard infrequently or may be unrecognized
by observers. The ksew call is a variable
call that can be confused with the skiew
of the Boreal Owl. This species is named for its
“saw-whet” call, but there is much debate over
which vocalization this refers to.
61. Male advertising song. Northern
Saw-whet Owls use this monotonous song in
territorial establishment and mate attraction.
The male sometimes sings it from prospective
nest holes. The female sometimes sings a softer,
less-consistent version. (Oregon, Geoffrey
A. Keller, ML 42199)
62. Advertising song. A young adult, possibly
a female, may have uttered this sporadic
version. (New York, Thomas Knight, ML
89405)
63. Whine-like call. (Utah, Kevin J. Colver,
BLB 28001)
64. Various calls recorded in fall. The first
two series are ksew calls; the third series
includes the high-pitched whine call and
whine-like calls similar to those on Disc 2,
Track 63. Both ksew and whine calls are often
23
heard in response to broadcast of the primary
song. The final call is an unknown wail, possibly
a whine in flight. (Pennsylvania, Scott
Weidensaul, 10/26/04 & 11/9/04)
65. Calls recorded in winter. (Pennsylvania,
Steve Farbotnik, 1/7/79 & 3/3/78)
66. Alarm call of male in response to an
intruder near the nest. (Pennsylvania, Steve
Farbotnik, 5/23/78)
67. Unknown call. Captive. (New York,
Robert W. Dickerman, ML 8330)
68. Bill snap and twittering chitter. Captive.
(Ontario, William W. H. Gunn, ML 61810)
69. Food deliveries at a nest. In the first
sequence, nestling chitter calls and weak begging
calls are audible, followed by the male
delivery call, a series of toots announcing a
food delivery at the nest. In the second delivery
sequence, the difference between the begging
calls of two nestlings at different levels of
development is apparent. (Pennsylvania, Steve
Farbotnik, 6/21/78)
DISC 2
Gerrit Vyn

Long-eared Owl Asio otus
The diverse repertoire of the Long-eared
Owl is primarily heard during the breeding
season from late winter though spring. It
uses a remarkable number of highly variable
alarm and aggression calls that are most often
heard around the nest. These vocalizations
reflect a range of intensity and emotion in
relation to many factors such as the type of
threat, stage of nest development, and previous
experience of the adults. Calls tend to be
most vigorous in the latter stages of breeding
when the young are flightless but have left
the nest. Long-eared Owls are considered to
be quiet during the nonbreeding season but
they are known to vocalize in the vicinity of
winter roosts, suggesting that further study is
needed. This species is also known to perform
elaborate display flights.
70. Male advertising song. Males use this
deep hooting song to attract a mate and
announce a territory. Male hooting is also
commonly used in alarm and is one of the
first calls researchers hear when approaching
a nest. (Washington, David S. Herr, ML
49057)
71. Female nest call. The female uses this
variable call at the nest or its immediate vicinity.
It may be a food solicitation call. It
is heard in early spring during the period of
24
nest selection and through the early portion
of nesting. It is often uttered in response to
the male’s song or wing-clapping. (California,
Thomas G. Sander, ML 110984)
72. Female nest call. This example has a
sighing element. (New York, Lang Elliott,
3/22/92)
73. Pair duet with the female nest call in the
foreground. The male’s advertising song is
more distant. (Washington, David S. Herr,
ML 48901)
74. Male wing-clap and female nest call.
Females often use the nest call in response
to the male’s wing-clap display flight. Males
perform an erratic buoyant flight through the
trees, interspersed with wing-claps below the
body. These flights sometimes circle a newly
selected nest site as the female responds from
the nest with the nest call. Males also wingclap
in nest defense. (Washington, David S.
Herr, ML 47531)
75. Male barking alarm call at a nest. This is
the most common call used in alarm at the
nest. This call is also known to express other
types of agitation. (New Jersey, George B.
Reynard, ML 8344)
76. Female barking alarm call at
a nest. (New Jersey, George B.
Reynard, ML 8350)
77. Alarm call at a nest. (New
Jersey, George B. Reynard, ML
8350)
78. High intensity alarm call and
bill-clap at a nest. (Manitoba, Lang
Elliott, 6/13/93)
79. Alarm call given in flight near a
threatened nest. (George B.
Reynard, ML 8350)
80. Low intensity alarm call and
bill-clap at a nest. These vocalizations
are often accompanied by the
forward-threat posture. (New Jersey,
George B. Reynard, ML 8350)
81. Distraction squeal by a highly
alarmed bird at a nest. (Manitoba,
Lang Elliott, 6/13/93)
82. Bill-clap and hiss by an alarmed
bird at a nest. (New Jersey, George
B. Reynard, ML 8350)
83. Fledgling begging call.
(Vermont, Matthew D. Medler, ML
126495)
DISC 2
Gerrit Vyn

Short-eared Owl Asio flammeus
The Short-eared Owl’s reputation as a quiet
bird is undeserved. Even in winter, birds commonly
vocalize when interacting and foraging.
The male’s courtship flight, wing-clapping,
and hooting during courtship, are also contrary
to this reputation. Males have lower
pitched voices than females, but this difference
is not as pronounced as it is in most other owl
species. Bark-like calls are used frequently and
are quite variable, probably representing several
unique vocalizations. Further research is
needed to classify these calls and describe their
behavioral contexts.
84. Male primary song and wing-clap. This
hooting song is usually heard in late winter
and early spring on the breeding grounds.
Males generally utter it during their courtship
flights, often as they hover into the wind.
Perched birds also use it, especially after a
courtship flight. The elaborate courtship
flight includes many rapid series of wing-claps
beneath the body, as heard here. Birds may
also wing-clap in nest defense and during
territorial skirmishes. (Alaska, Brian J.
McCaffery, ML 50052)
85. Bark call by an owl in flight. (Oregon,
David S. Herr, ML 45302)
25
86. Bark calls by a flying owl in response to
intruders near a nest. (Manitoba, Arthur A.
Allen and Peter Paul Kellogg, ML 22671)
87. Bark call by a perched owl near a communal
winter roost. (New York, Gerrit Vyn,
ML 128922)
88. Bark call in flight during antagonistic
encounters between hunting birds in winter.
These calls were made by a bird harassing
both flying and perched individuals. (New
York, Gerrit Vyn, ML 128922)
89. Female distraction call and bill-clap in
response to a nest intruder. In cases of high
intensity alarm at the nest, both sexes utter various
squealing calls during an injury-feigning or
distraction display. (Manitoba, Arthur A. Allen
and Peter Paul Kellogg, ML 22672, 22674)
90. Fledgling begging call. Captive.
(Manitoba, Richard J. Clark, ML 22683)
91. Fledgling chitter call. Captive.
(Manitoba, Richard J. Clark, ML 22683)
DISC 2
Gerrit Vyn

Extralimital Species
Mottled Owl Strix virgata
This widespread and common Latin
American species finds its northern limits in
Mexico about 80 miles south of the Texas
border. It has been recorded once in the
United States, near Bentsen-Rio Grande
Valley State Park, where a bird was found
dead on a roadside. Like the Barred Owl, the
Mottled Owl is known to be highly vocal and
produces a wide variety of sounds.
92. Male advertising song or territorial hooting.
(Chiapas, Mexico, Curtis A. Marantz,
ML 127206)
26
Stygian Owl Asio stygius
The Stygian Owl is an elusive species with
a patchy distribution from north-central
Mexico to northern Argentina and parts of
the Caribbean. It has been seen on two occasions
at Bentsen-Rio Grande Valley State Park
in southern Texas. Like the similar Longeared
Owl, this species is known to produce a
wing-clap in display flight.
93. Male advertising song or hoot with female
call in response. This sequence may be analogous
to the male advertising song and female
nest call duet of Long-eared Owl (Disc 2, Track
73). Common Paraque (Nyctidromus albicollis)
is vocalizing prominently in the background.
(Belize, George B. Reynard, 3/21/75)
Alphabetized Species List And Vocalization Types
Species are listed alphabetically. Vocalizations are preceded by disc number and track number. They
are listed in the order in which they appear on the CD.
Owl, Barn
1.1 Territorial scream
1.2 Territorial scream
1.3 Territorial scream, wing-clap
1.4 Warning scream
1.5 Distress call
1.6 Sustained defensive hiss, bill-clap,
warning scream
1.7 Sustained defensive hiss
1.8 Kleak-kleak call
1.9 Calls at nest
1.10 Fledgling mobbing call
1.11 Fledgling begging snore
Owl, Barred
1.91 Female two-phrase hoot, ascending
hoot, caterwaul
1.92 Pair caterwauling
1.93 Pair caterwauling
1.94 Female two-phrase hoot, male
ascending hoot, female hoot variation
1.95 Ascending hoot, two-phrase hoot,
caterwaul
1.96 Ascending hoot, caterwaul, hoo-aw
1.97 Male hoo-aw
1.98 Female hoo-aw
1.99 Female hoot variation
2.1 Female solicitation call
2.2 Distraction squeals and honk
2.3 Fledgling begging call
2.4 Fledgling begging call, male
two-phrase hoot
Owl, Barred x Spotted
1.90 Advertisement hooting
Owl, Boreal
2.53 Male staccato song
2.54 Male prolonged staccato song
2.55 Male subdued staccato song
2.56 Skiew call
2.57 Male food delivery call
2.58 Nestling peep, male food delivery call
2.59 Nestling chatter, female peep
2.60 Fledgling begging call, male food
delivery call, skiew call
Owl, Burrowing
2.47 Male primary song
2.48 Alarm chatter
2.49 Alarm notes, alarm chatter
2.50 Alarm chatter
2.51 Nestling begging rasp, adult
alarm chatter
2.52 Juvenile rattlesnake rasp
Owl, Elf
2.41 Male chatter song, female station call
2.42 Prolonged male chatter song,
female call
2.43 Bark call, station call
2.44 Bark call
2.45 Copulation
2.46 Nestling begging rasp

Owl, Flammulated
1.12 Male territorial hoot
1.13 Female hoot
1.14 Nestling begging snore, adult food
delivery hoot
1.15 Female bark, nestling begging snore
1.16 Male bark
1.17 Female moan
1.18 Distress shriek, bill-clap
Owl, Great Gray
2.5 Male territorial hoot
2.6 Defensive hoot
2.7 Defensive hoot
2.8 Male contact hoot
2.9 Female contact call
2.10 Female contact call, nestling
begging call
2.11 Chitter call
2.12 Distraction calls
2.13 Agitated call
2.14 Fledgling begging call, hoot
2.15 Food exchange at nest
2.16 Fledgling begging call
Owl, Great Horned
1.44 Territorial hooting duet
1.45 Territorial hooting duet, copulation
1.46 Female squawk, male territorial hoot
1.47 Female chitter call, squawk,
male territorial hoot
1.48 Male territorial hoot, female
territorial hoot, squawk
1.49 Bark-like call
27
1.50 Female wac-wac call, bill-clap,
male hoot
1.51 Chitter call
1.52 Fledgling begging call
Owl, Long-eared
2.70 Male advertising hoot
2.71 Female nest call
2.72 Female nest call
2.73 Female nest call, male
advertising hoot
2.74 Male wing-clap, female nest call
2.75 Male bark
2.76 Female bark
2.77 Alarm call
2.78 High intensity alarm call, bill-clap
2.79 Alarm call in flight
2.80 Low intensity alarm call, bill-clap
2.81 Distraction squeal
2.82 Bill-clap, hiss
2.83 Fledgling begging call
Owl, Mottled
2.92 Male territorial hoot
Owl, Northern Hawk
2.17 Male advertising song
2.18 Trilling call
2.19 Screeching call, yelping call
2.20 Alarm squeals
2.21 Distress call
Owl, Northern Saw-whet
2.61 Male advertising song
2.62 Advertising song
2.63 Whine-like call
2.64 Ksew call, whine call, whine-like call
2.65 Calls
2.66 Male alarm call
2.67 Unknown call
2.68 Bill snap, chitter call
2.69 Food deliveries at nest
Owl, Short-eared
2.84 Male hoot, wing-clap
2.85 Bark call
2.86 Bark call
2.87 Bark call
2.88 Bark call
2.89 Female distraction call, bill-clap
2.90 Fledgling begging call
2.91 Fledgling chitter call
Owl, Snowy
1.53 Male territorial hoot
1.54 Female bark call, bill snap
1.55 Male bark call
1.56 Female mewing whistle
1.57 Unidentified call
1.58 Unidentified call
1.59 Nestling begging squeal, chitter call
1.60 Fledgling begging call, chitter
Owl, Spotted (“Mexican”)
1.75 Male four-note location call
1.76 Male four-note location call
1.77 Female four-note location call
1.78 Female agitated location call,
male four-note location call, female
agitated contact whistle
1.79 Agitated location call
1.80 Male series location call
1.81 Male series location call
1.82 Whistle contact call
1.83 Agitated contact whistle
1.84 Bark series
1.85 Cooing call
1.86 Contact-like call, bark
1.87 Copulation
1.88 Prey delivery
1.89 Fledgling begging call
Owl, Spotted (“Northern”)
1.61 Male four-note location call
1.62 Female four-note location call
1.63 Female three-note location call
1.64 Male five-note location call
1.65 Male series location call, female
contact whistle
1.66 Female series location call
1.67 Female series location call, agitated
contact whistle
1.68 Male series location call, female
contact whistle
1.69 Contact whistle
1.70 Female agitated contact whistle
1.71 Female bark series
1.72 Female contact whistle, male nest call
1.73 Pair interaction
1.74 Pair interaction
Owl, Stygian
2.93 Male advertising hoot, female call
Pygmy-Owl, Ferruginous
2.32 Male primary advertising song

2.33 Female primary advertising song
2.34 Male primary advertising song,
prolonged chitter call, female
chitter call
2.35 Female chitter call
2.36 Female alarm call
2.37 Female aggression call
2.38 Female aggression call
2.39 Nestling distress call
2.40 Fledgling begging chitter
Pygmy-Owl, Northern
2.22 Male toot song (G.g. grinnelli)
2.23 Male toot song (G.g. californicum)
2.24 Male toot song (G.g. gnoma)
2.25 Male double-note toot song
(G.g. gnoma)
2.26 Male toot song, prolonged chitter
call, female chitter call
2.27 Female chitter call
2.28 Copulation
2.29 Food delivery at nest
2.30 Female chitter call, unknown call
2.31 Fledgling begging call
Screech-Owl, Eastern
1.24 Descending trill, monotonic trill
1.25 Descending trill
1.26 Monotonic trill
1.27 Monotonic trill
1.28 Monotonic trill
1.29 Screech call, bill-clap
1.30 Screech call, chuckle rattle
1.31 Bark call
28
1.32 Nestling begging rasp, chitter call,
chuckle rattle
1.33 Food delivery at nest
Screech-Owl, Western
1.19 Bouncing ball song, double trill song
1.20 Double trill song, bouncing ball song
1.21 Agitated bark, bill-clap
1.22 Te-te-do call, agitated double trill
1.23 Female solicitation call
Screech-Owl, Whiskered
1.34 Male short trill
1.35 Male short trill
1.36 Male telegraphic trill
1.37 Telegraphic trill, squeal
1.38 Male prolonged trill
1.39 Hoot
1.40 Male whistle call
1.41 Bark series
1.42 Female bark call, screech
1.43 Copulation
GERRIT VYN
Producer / Studio Engineer / Sound Selector / Text Author
GREGORY F. BUDNEY
Co-Producer
MARY GUTHRIE
Production Manager
ROBERT W. GROTKE
Supervising Engineer
Front and back cover photographs courtesy of Gerrit Vyn
Macaulay Library
Cornell Laboratory of Ornithology
159 Sapsucker Woods Rd.
Ithaca, New York 14850
Tel. (607) 254-2404
email: macaulaylibrary@cornell.edu
© 2006 Cornell Laboratory of Ornithology