Voices of North American Owls - Macaulay Library
Voices of North American Owls - Macaulay Library
Voices of North American Owls - Macaulay Library
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<strong>Voices</strong> <strong>of</strong> <strong>North</strong> <strong>American</strong> <strong>Owls</strong><br />
This comprehensive audio guide presents nearly 200<br />
recordings <strong>of</strong> <strong>North</strong> America’s 19 regularly occurring owl species<br />
plus two rarities. With a booklet containing detailed text and<br />
color photographs, this collection illuminates for the first time<br />
the diversity <strong>of</strong> owl vocalizations in <strong>North</strong> America.<br />
“The best <strong>of</strong> the best, my kind <strong>of</strong> CD production, as it takes me<br />
well beyond identifying owls by their sounds to understanding<br />
owls by their sounds. I can’t wait till my next owl encounter, as I’ll<br />
listen in a whole new way.”<br />
Donald Kroodsma, author <strong>of</strong> The Singing Life <strong>of</strong> Birds<br />
“Cornell’s <strong>Voices</strong> <strong>of</strong> <strong>North</strong> <strong>American</strong> <strong>Owls</strong> is the most comprehensive<br />
and detailed treatment <strong>of</strong> this subject to date and will serve as the benchmark reference for years to<br />
come. It documents that owl vocalizations are more complex than we imagined, and will both train<br />
and stimulate a new generation <strong>of</strong> owl biologists and naturalists to better understand, appreciate,<br />
research, and conserve these fascinating creatures. Find a place in your CD collection for this<br />
volume—you will not regret it!”<br />
Dr. James R. Duncan, author <strong>of</strong> <strong>Owls</strong> <strong>of</strong> the World<br />
“<strong>Voices</strong> <strong>of</strong> <strong>North</strong> <strong>American</strong> <strong>Owls</strong> opens up the world <strong>of</strong> the night—a treasure-trove <strong>of</strong> strange, lovely and<br />
sometimes hair-raising owl vocalizations, from the courtship wing-clap and hooting <strong>of</strong> a pair <strong>of</strong> Long-eared<br />
<strong>Owls</strong> to the tooting food-delivery calls <strong>of</strong> a <strong>North</strong>ern Saw-whet Owl in an eastern forest and the chatter <strong>of</strong><br />
an Elf Owl in the Arizona desert. By far the most comprehensive collection <strong>of</strong> <strong>North</strong> <strong>American</strong> owl vocalizations<br />
ever produced, it features not just common territorial songs, but many lesser known vocalizations,<br />
including alarm calls, juvenile food-begging cries, contact calls, and more. <strong>Voices</strong> <strong>of</strong> <strong>North</strong> <strong>American</strong> <strong>Owls</strong> is<br />
a must for anyone who wants to know what goes bump (and toot, and screech, and hiss) in the night.”<br />
Scott Weidensaul, author <strong>of</strong> Living on the Wind<br />
ISBN 0-938027-66-2
2<br />
“I rejoice that there are owls. Let them do the idiotic and maniacal hooting for men.<br />
It is a sound admirably suited to swamps and twilight woods which no day illustrates,<br />
suggesting a vast and undeveloped nature which men have not recognized. They represent<br />
the stark twilight and unsatisfied thoughts which all have.”<br />
Introduction<br />
<strong>Owls</strong> have persisted in man’s cultural<br />
consciousness since the beginning <strong>of</strong><br />
time. From the earliest cave paintings<br />
through modern times, owls have<br />
appeared in artifacts, myth, folklore, and<br />
legend. They represent a broad spectrum<br />
<strong>of</strong> meanings for different cultures and<br />
individuals around the world—regarded<br />
by some as symbols <strong>of</strong> wisdom and<br />
godliness, and by others as harbingers <strong>of</strong><br />
death. Few birds or other animals<br />
capture our minds and imaginations to<br />
the degree that owls do.<br />
Our emotional response to owls is <strong>of</strong>ten<br />
attributed to their human-like appearance.<br />
Their large forward-facing eyes and<br />
Henry David Thoreau, Walden<br />
expressive faces have contributed greatly<br />
to the lore surrounding them. Less <strong>of</strong>ten<br />
considered, but perhaps even more<br />
significant, are the sounds owls make.<br />
From the earliest hunter-gatherers sitting<br />
in darkness around a fire, to scientific researchers<br />
today, owl sounds in the night<br />
have presented a mystery to be feared or<br />
a question to be answered. Remarkably<br />
we still know little about owls and the<br />
meaning <strong>of</strong> their sounds. This compilation<br />
aims to shed new light on the<br />
intricacies <strong>of</strong> owl vocal behavior and to<br />
aid ornithologists and bird- watchers in<br />
detecting and identifying these denizens<br />
<strong>of</strong> the night. It is also hoped that the<br />
listener will gain a greater appreciation
for owls and the importance <strong>of</strong> conserving<br />
the habitats where they live.<br />
The Sounds <strong>Owls</strong> Make<br />
Primarily nocturnal, and <strong>of</strong>ten living in<br />
dark forested environments, owls rely<br />
heavily on sound both to find prey and<br />
to communicate. Most owls are built to<br />
receive sound, enabling them to locate<br />
prey aurally with great accuracy. They<br />
have also evolved rich repertoires <strong>of</strong><br />
vocalizations for communicating in the<br />
dark. These vocalizations are inherited<br />
and in many instances convey precise<br />
meanings to other owls. Upon hatching,<br />
young Barred <strong>Owls</strong> give specific<br />
calls that communicate hunger to their<br />
parents and stimulate the adults to feed<br />
them (Track 103). Though the character<br />
<strong>of</strong> this vocalization changes as young<br />
birds grow, it still carries its precise<br />
meaning; adult females use it to solicit<br />
food from their mates. (Track 100).<br />
3<br />
<strong>Owls</strong> use songs primarily for territorial<br />
proclamation, territorial defense, and<br />
mate attraction and bonding. Songs<br />
generally consist <strong>of</strong> multiple notes with<br />
intervals between notes usually less than<br />
twice the note duration. Typically they<br />
have high harmonics.<br />
Owl calls are used in a variety <strong>of</strong> other<br />
contexts such as begging, alarm, or aggression.<br />
Calls are generally single notes<br />
with longer intervals between notes.<br />
With a few exceptions, calls generally lack<br />
harmonics. Calls <strong>of</strong>ten vary significantly<br />
depending on an owl’s age, motivation, or<br />
stimuli. It is also common for a vocalization<br />
seemingly identical to a species’<br />
song, or a derivative <strong>of</strong> that vocalization,<br />
to be used as a call, such as hooting by<br />
male Long-eared and Snowy owls in nest<br />
defense.<br />
Although most owl species’ songs are<br />
unique, such as the low hooting <strong>of</strong> a<br />
Great Horned Owl or the whinny <strong>of</strong> an<br />
Eastern Screech-Owl, some calls appear<br />
to be used in similar contexts by many<br />
owl species. The discomfort call, <strong>of</strong>ten<br />
referred to as a “chitter” by researchers,<br />
is most <strong>of</strong>ten uttered by both adults and<br />
young when in close association with<br />
other owls or when being handled by<br />
researchers. This call commonly communicates<br />
discomfort, including hunger,<br />
but is also used during mutual preening<br />
(allopreening), food transfers, and<br />
copulation. Most owl species seem to<br />
produce analogous variations <strong>of</strong> this call<br />
under similar stimuli. Other similarities<br />
in calls <strong>of</strong> different species suggest other<br />
analogous call-types may exist. A system<br />
<strong>of</strong> naming and classifying these vocalizations<br />
is useful for standardizing the way<br />
that we talk about owl vocalizations.<br />
Some suggestions for alternate naming<br />
<strong>of</strong> vocalizations have been included in<br />
this production.<br />
About This Audio Guide<br />
Some selections on this guide were made<br />
strictly to illustrate particular vocalizations,<br />
some to illustrate behavioral<br />
sequences, and others for sheer listening<br />
pleasure. Therefore the length and quality<br />
<strong>of</strong> recordings within this production<br />
vary. Although every effort was made<br />
to include all known vocalizations for<br />
each species, many vocalizations remain<br />
unrecorded or unavailable. There are<br />
also vocalizations that have yet to be<br />
described or have only been described<br />
phonetically. This has made identification<br />
<strong>of</strong> many previously described calls<br />
and associated behavior problematic.<br />
Additionally, observing behavior associated<br />
with vocalizations <strong>of</strong> nocturnal<br />
animals is inherently difficult. Therefore<br />
the repertoire presented for each species<br />
should be considered incomplete and<br />
the accompanying text for each vocalization<br />
a conservative interpretation <strong>of</strong><br />
the available literature. Behavioral
contexts are described when known<br />
but should not be considered the only<br />
circumstances in which a species may<br />
use a particular vocalization. Though<br />
names given by researchers to some<br />
vocalizations can be misleading as to<br />
the function, we have tried to include<br />
the names by which many <strong>of</strong> the calls<br />
presented here are commonly known.<br />
For a more comprehensive written<br />
treatment <strong>of</strong> owl vocalizations, consult<br />
the additional references listed in this<br />
booklet. Track 1 contains a sample<br />
track <strong>of</strong> the guide.<br />
Playing Recordings In The Field<br />
The greatest care should be taken when<br />
using recordings <strong>of</strong> owls and other birds<br />
in the field. Playback <strong>of</strong> these recordings<br />
should be done responsibly, particularly<br />
during the breeding season when owls<br />
are most vocal. Some recordings on this<br />
guide, especially distress and alarm calls,<br />
could cause undue stress and should<br />
4<br />
never be played in the field. One <strong>of</strong> the<br />
most fulfilling ways to experience owls at<br />
night is simply to go out and listen.<br />
Acknowledgements<br />
We extend our thanks and gratitude<br />
to those individuals and organizations<br />
that have helped us in the development<br />
<strong>of</strong> this audio guide. Tom Weber <strong>of</strong><br />
the Florida Museum <strong>of</strong> Natural History<br />
(FMNH), Jill Soha <strong>of</strong> the Borror<br />
Laboratory <strong>of</strong> Bioacoustics (BLB) at<br />
The Ohio State University, and Chantal<br />
Dussault <strong>of</strong> the Canadian Museum <strong>of</strong><br />
Nature (CMN), kindly searched their<br />
archives and provided unique recordings<br />
for this production. Thank you to<br />
Jack W. Bradbury and Sean O’Brien<br />
for reviewing the text in its entirety and<br />
providing valuable insights and additions.<br />
Our sincerest thanks also to those<br />
who provided their expertise, time, and<br />
knowledge in reviewing portions <strong>of</strong><br />
the species text and associated record-<br />
ings: Frederick R. Gehlbach, James R.<br />
Duncan, Robert W. Nero, Glenn A.<br />
Proudfoot, Denver W. Holt, Eric D.<br />
Forsman, D. Archibald McCallum,<br />
Bernard Lohr, Karla Kinstler, Richard<br />
J. Cannings, Gregory D. Hayward,<br />
Douglas E. Trapp, and Tony Angell.<br />
An additional thanks to Glenn A.<br />
Proudfoot and Bernard Lohr for their<br />
visits to the <strong>Macaulay</strong> <strong>Library</strong> during<br />
the development <strong>of</strong> this audio guide,<br />
and for archiving new field tapes for use<br />
in this production. Finally, our sincerest<br />
gratitude to the contributing recordists.<br />
Without their nocturnal forays, this<br />
guide would not have been possible.<br />
Contributing Recordists<br />
Arthur A. Allen, Harriette Barker, Charles<br />
M. Bogert, Kent Bovee, Meredith Bovee,<br />
Gregory F. Budney, Greg Clark, Richard<br />
J. Clark, Benjamin M. Clock, Kevin J.<br />
Colver, L. Irby Davis, Robert W.<br />
Dickerman, Lang Elliott, William R. Ev-<br />
ans, Steve Farbotnik, Robert C. Faucett,<br />
William R. Fish, J. R. Fletcher, Frederick<br />
R. Gehlbach, William W. H. Gunn,<br />
David S. Herr, Wilbur L. Hershberger,<br />
Virginia Huber, Albert Karvonen, Ge<strong>of</strong>frey<br />
A. Keller, Peter Paul Kellogg, Thomas<br />
Knight, Wendy Kuntz, Greg Lasley, J.<br />
David Ligon, Randolph S. Little, Bernard<br />
Lohr, Stewart D. MacDonald, Curtis A.<br />
Marantz, Joseph T. Marshall Jr., Brian<br />
J. McCaffery, D. Archibald McCallum,<br />
Hugh P. McIsaac, Matthew D. Medler,<br />
Rosa Meehan, Martin C. Michener, Sean<br />
O’Brien, Sture Palmer, Leonard J. Peyton,<br />
Tim Price, Glenn A. Proudfoot, George<br />
B. Reynard, Jeffrey Rice, Robert Righter,<br />
Andres M. Sada, Thomas G. Sander, David<br />
T. Spaulding, Sally Sp<strong>of</strong>ford, Robert<br />
C. Stein, Charles A. Sutherland, Gerrit<br />
Vyn, Scott Weidensaul, and Steven G.<br />
Wilson.
Resources And Bibliography<br />
The Birds <strong>of</strong> <strong>North</strong> America Online<br />
www.bna.birds.cornell.edu<br />
Johnsgard, P. A. <strong>North</strong> <strong>American</strong> <strong>Owls</strong>:<br />
Biology and Natural History, 2nd edition.<br />
Washington, D.C.: Smithsonian Institution;<br />
2002.<br />
Duncan, J. R. <strong>Owls</strong> <strong>of</strong> the World: Their<br />
Lives, Behavior, and Survival. Buffalo,<br />
NY: Firefly Books; 2003.<br />
König, C., F. Weick, and J. Becking.<br />
<strong>Owls</strong>: A Guide to <strong>Owls</strong> <strong>of</strong> the World. New<br />
Haven, CT: Yale University Press; 1999.<br />
Owl Research Institute, an organization<br />
dedicated to owl research,<br />
conservation, and public education<br />
www.owlinstitute.org<br />
5<br />
The Owl Foundation, a center for the<br />
rehabilitation <strong>of</strong> Canadian owl species<br />
and the behavioral observation <strong>of</strong><br />
permanently damaged wild owls in a<br />
breeding environment<br />
www.theowlfoundation.ca<br />
A Note To Recordists<br />
And Researchers<br />
This guide represents a first step in<br />
classifying and disseminating the songs<br />
and calls <strong>of</strong> <strong>North</strong> <strong>American</strong> owls.<br />
Researchers and recordists are invited<br />
to contribute their recordings for future<br />
editions <strong>of</strong> this guide and to provide<br />
any written insights into the material<br />
presented here. We hope that this collection<br />
will serve as a working reference<br />
for those describing and studying owl<br />
vocalizations and behavior.<br />
For production purposes, changes to<br />
inter-song interval and other edits<br />
have been made to some recordings.<br />
For research purposes, please visit our<br />
website to obtain source recordings. Our<br />
complete audio catalogue is available for<br />
listening and spectrographic anaysis at<br />
www.macaulaylibrary.org.<br />
The preservation and study <strong>of</strong> acoustic<br />
communication recordings <strong>of</strong> birds and<br />
other animals is the focus <strong>of</strong> the <strong>Macaulay</strong><br />
<strong>Library</strong> at the Cornell Lab <strong>of</strong> Ornithology.<br />
To learn more about how wildlife recordings<br />
are made, how to participate in this work,<br />
and how to become a member <strong>of</strong> the Cornell<br />
Lab <strong>of</strong> Ornithology, please contact us.<br />
<strong>Macaulay</strong> <strong>Library</strong><br />
Cornell Lab <strong>of</strong> Ornithology<br />
159 Sapsucker Woods Road<br />
Ithaca, NY 14850<br />
telephone: (607) 254-2404<br />
email: macaulaylibrary@cornell.edu<br />
website: www.macaulaylibrary.org<br />
Interpreting and conserving the earth’s<br />
biological diversity through research, education,<br />
and citizen science focused on birds
VOICES OF NORTH AMERICAN OWLS TRACK LIST<br />
Barn Owl Tyto alba<br />
The Barn Owl’s screams, pale ghostlike appearance,<br />
and inhabitation <strong>of</strong> abandoned<br />
buildings, farms, and church belfries have<br />
probably contributed to superstitions about<br />
owls around the world. Barn <strong>Owls</strong> are vocally<br />
active when breeding and use a wide<br />
repertoire <strong>of</strong> acoustic signals. Most <strong>of</strong> their<br />
vocalizations fall into the category <strong>of</strong> hisses<br />
and screams, with different calls <strong>of</strong>ten grading<br />
into each other. This makes it difficult to<br />
distinguish between subtly different calls, describe<br />
them phonetically, and associate them<br />
with a specific behavior. Female screams are<br />
generally huskier and less consistently given<br />
than male screams, but sexing individuals<br />
based on this is generally not definitive.<br />
Track Number/Description<br />
2. Territorial scream or advertising call.<br />
A male probably produced this call, described<br />
as karr-r-r-r-r-ick. (California, Ge<strong>of</strong>frey A.<br />
Keller, ML 50147)<br />
3. Territorial scream or advertising call.<br />
Described as shrrreeeeee, this call was probably<br />
made by a female. (Washington, David S.<br />
Herr, ML 50540)<br />
4. Territorial screams and wing-clap display.<br />
The first scream is probably by a male, the<br />
second by a female. (New York, Charles A.<br />
Sutherland, ML 8323)<br />
6<br />
5. Warning scream, or alarm call <strong>of</strong> an adult.<br />
(Washington, David S. Herr, ML 50541)<br />
6. Distress call <strong>of</strong> a captive owl. This call<br />
indicates intense distress or fear such as when<br />
an owl has been seized or is in an intense<br />
fight. (New York, Martin C. Michener, ML<br />
8320)<br />
7. Sustained defensive hiss, bill-clap, and<br />
warning scream by captive advanced nestlings.<br />
(New York, Sally Sp<strong>of</strong>ford, ML 8325)<br />
8. Sustained defensive hiss by an adult. <strong>Owls</strong><br />
<strong>of</strong>ten use this call when threatened or cornered,<br />
<strong>of</strong>ten accompanied by threat postures.<br />
If the danger persists, this call <strong>of</strong>ten grades<br />
into the distress call. These calls and the related<br />
postures are intended to intimidate predators.<br />
Captive. (New York, Peter Paul Kellogg,<br />
ML 8319)<br />
9. Kleak-kleak call. The male commonly utters<br />
this call in flight during nesting, <strong>of</strong>ten to<br />
announce food deliveries to the nest.<br />
(California, Robert C. Stein, ML 8322)<br />
10. Calls recorded at a nest. The behavioral<br />
context for this recording is unknown but<br />
calls suggesting the food-<strong>of</strong>fering call and<br />
adult begging snore are heard in this recording.<br />
A male may have been delivering food to<br />
an incubating female. (California, William R.<br />
Fish, ML 22812)<br />
11. Fledgling mobbing call.<br />
<strong>Owls</strong> usually direct this scolding<br />
call toward terrestrial predators,<br />
including humans. A<br />
second fledgling is audible, uttering<br />
begging snores. (Florida,<br />
Gerrit Vyn, ML 104569)<br />
12. Fledgling begging snore.<br />
Juvenile and female owls<br />
use this self-advertising call.<br />
The calls’ intensity increases<br />
with hunger and the arrival<br />
<strong>of</strong> adults with food. Hungry<br />
fledglings will give this call<br />
persistently throughout the<br />
night. (Florida, Gerrit Vyn,<br />
ML 104569)<br />
Juan Bahamon
Flammulated Owl Otus flammeolus<br />
Although the Flammulated Owl is one or our<br />
smallest owls, its hoot is one <strong>of</strong> the lowestfrequency<br />
owl songs in <strong>North</strong> America. The<br />
male’s hoot also has a ventriloquial quality,<br />
making it difficult to observe this small, cryptically<br />
colored, nocturnal owl. The owls also<br />
vary the amplitude <strong>of</strong> their hoots, making it<br />
difficult to judge the distance to a calling owl.<br />
The vocalizations <strong>of</strong> adult Flammulated <strong>Owls</strong><br />
consist <strong>of</strong> one basic note type which grades<br />
from short hoots to long shrieks, with many<br />
variations in between. These varied intermediate<br />
calls are commonly described as barks<br />
and moans.<br />
13. Male territorial hoot or advertising song.<br />
Males primarily give the single-note hoot<br />
when singing. When a male is agitated, such<br />
as when another male invades a territory,<br />
the hoot may be accompanied by additional<br />
notes, or may become more quiet, hoarse,<br />
and with multiple notes, as is heard in the<br />
last call here. (Oregon, David S. Herr, ML<br />
47540)<br />
14. Female hoot. A female uttered these<br />
hoots as she solicited courtship feedings<br />
from a male. (New Mexico, D. Archibald<br />
McCallum, 5/12/81)<br />
7<br />
15. Begging snores <strong>of</strong> nestlings and low amplitude<br />
hoot given by an adult announcing<br />
a food delivery to the nest. Adults also use<br />
low amplitude hoots as a contact call between<br />
mates. (Oregon, David S. Herr, ML 50536)<br />
16. Bark by an alarmed female, and nestling<br />
begging snore. Barking can escalate into a variety<br />
<strong>of</strong> screams and shrieks depending on an<br />
owl’s level <strong>of</strong> agitation or aggression. (Oregon,<br />
David S. Herr, ML 50536)<br />
17. Male bark in response to a human<br />
intruder near a pair. (New Mexico, D.<br />
Archibald McCallum, 4/29/03)<br />
18. Female moan. (New Mexico, D.<br />
Archibald McCallum, 7/6/83)<br />
19. Distress shriek and bill-clap <strong>of</strong> an injured<br />
bird. (Texas, Greg Lasley, FMNH 1288)<br />
Brian E. Small
Western Screech-Owl Megascops kennicotti<br />
Like other <strong>North</strong> <strong>American</strong> screech-owls, the<br />
Western Screech-Owl uses two song types.<br />
The bouncing ball song is used for territorial<br />
advertisement and defense. The double trill is<br />
a mate coordination song and is heard more<br />
frequently in pair duetting. Males sing most<br />
<strong>of</strong>ten in winter and early spring prior to egglaying.<br />
They <strong>of</strong>ten sing from potential nest<br />
cavities or nest trees. Singing increases again<br />
in late summer as young disperse from adult<br />
territories. Both sexes share the adult vocalizations,<br />
with the female having a noticeably<br />
higher voice.<br />
20. Pair duet. Bouncing ball and double trill<br />
songs are given by both sexes. The female’s<br />
voice is higher pitched. Various unidentified<br />
calls are audible during an interaction<br />
between a pair at the end <strong>of</strong> the recording. Elf<br />
Owl (Micrathene whitneyi) barks are also audible<br />
during the duet. (Arizona, Ge<strong>of</strong>frey A.<br />
Keller, ML 109017)<br />
21. Double trill song followed by bouncing<br />
ball song. Mates use the double trill as<br />
a contact call. The male also uses the double<br />
trill to announce food deliveries to the nest.<br />
(Washington, David S. Herr, ML 47692)<br />
22. Agitated bark and bill-clap. (Washington,<br />
David S. Herr, ML 63001)<br />
8<br />
23. Te-te-do call progressing into agitated<br />
double trill. This call requires further study<br />
but is known to be given by owls when confronted<br />
by others <strong>of</strong> the same species. It may<br />
be an intense proclamation <strong>of</strong> territory and<br />
is <strong>of</strong>ten combined with the double trill. It is<br />
also similar to the solicitation or begging call<br />
<strong>of</strong> females and juveniles. (Oregon, David S.<br />
Herr, ML 50549)<br />
24. Female solicitation call or begging whinny.<br />
The female uses this call to solicit feedings<br />
and copulation in the early stages <strong>of</strong> nesting<br />
and when incubating and brooding young.<br />
It is derived from the juvenile begging call.<br />
(Alaska, Kent and Meredith Bovee, 4/29/05)<br />
Robert McMorran
Eastern Screech-Owl Megascops asio<br />
The Eastern Screech-Owl uses its descending<br />
trill song, or whinny, mainly for territorial<br />
advertisement or defense. Adults most<br />
commonly use this song from the time when<br />
fledglings disperse in late summer until<br />
courtship begins again in mid-winter. The<br />
monotonic trill song establishes pair and family<br />
bonds and is primarily used during the<br />
courtship and pre-nesting period from midwinter<br />
through spring. The owls also produce<br />
variations <strong>of</strong> this song during copulation and<br />
nest-cavity advertising. Additionally, the male<br />
uses the song prior to food deliveries and the<br />
female uses it to induce fledging. Pair duets<br />
are common and neighboring males will also<br />
synchronize their singing. Considerable variation<br />
in both song types between individuals<br />
may serve in sexual and individual recognition.<br />
Both sexes utter all vocalizations, with<br />
the male’s voice noticeably lower.<br />
25. Descending trill or whinny, followed by<br />
the monotonic trill. The monotonic trill is<br />
a variable vocalization that sometimes has a<br />
bouncing quality as is heard in this example.<br />
At other times it is a more consistently delivered<br />
song. Captive. (New York, Hugh P.<br />
McIsaac, ML 20427)<br />
9<br />
26. Descending trill during territorial defense.<br />
(Maryland, Wilbur L. Hershberger,<br />
ML 100704)<br />
27. Monotonic trill with descending trill<br />
in the background. (Maryland, Wilbur L.<br />
Hershberger, ML 107446)<br />
28. Monotonic trill with evenly spaced notes.<br />
Chuck-will’s-widow (Caprimulgus carolinensis)<br />
is prominently audible in the background.<br />
(Florida, Ge<strong>of</strong>frey A. Keller, ML 105733)<br />
29. Monotonic trill <strong>of</strong> shorter duration<br />
by M.a. mccallii in South Texas. (Texas,<br />
Matthew D. Medler, ML 87462)<br />
30. Screech calls and bill-claps by agitated<br />
pair. (Maryland, Wilbur L. Hershberger, ML<br />
94524)<br />
31. Screech and chuckle rattle. Both nestlings<br />
and adults utter the chuckle rattle, generally<br />
signifying annoyance. Captive. (New York,<br />
Hugh P. McIsaac, ML 20428)<br />
32. Bark call. Captive. (New York, Hugh P.<br />
McIsaac, ML 20428)<br />
33. Begging rasps, chitter calls, and chuckle<br />
rattle <strong>of</strong> nestlings. (New York, Arthur A.<br />
Allen, ML 4451, 4452, 4451, 39893)<br />
34. Food delivery at a nest. (New York,<br />
Arthur A. Allen, ML 39890)<br />
Gerrit Vyn
Whiskered Screech-Owl Otus trichopsis<br />
The Whiskered Screech-Owl uses its short<br />
trill as a song for territorial proclamation<br />
and defense, as well as for pair bonding and<br />
contact. The telegraphic trill is a variable syncopated<br />
song <strong>of</strong>ten sung in duet by pairs. It<br />
is associated with pair contact, defense <strong>of</strong> territory,<br />
and copulation. Both sexes sing, with<br />
the female having a noticeably higher voice.<br />
Most singing occurs at night with peaks in<br />
singing at dusk and before sunrise. Like Elf<br />
<strong>Owls</strong> and other screech-owls, Whiskered<br />
Screech-<strong>Owls</strong> sing most frequently during<br />
gibbous to full moons on clear nights.<br />
35. Male short trill. The male uses this song<br />
in territorial defense and when advertising<br />
prospective nest cavities. (New Mexico,<br />
Curtis A. Marantz, ML 112621)<br />
36. Male short trill. (Arizona, Ge<strong>of</strong>frey A.<br />
Keller, ML 40588)<br />
37. Telegraphic trill <strong>of</strong> male. (Arizona, Greg<br />
Clark, 1/97)<br />
38. Telegraphic trill by a pair followed by a<br />
squeal during an encounter with an invading<br />
owl. Pairs also use this song in response to<br />
small singing owls <strong>of</strong> other species. (Arizona,<br />
Bernard Lohr, 5/31/99)<br />
10<br />
39. Male prolonged or long trill. This song<br />
is only known to be given by the male in the<br />
immediate vicinity <strong>of</strong> the nest cavity. It may<br />
signal intense territoriality. When a female<br />
is present, the call may become deeper and<br />
more guttural (not heard here). (Arizona,<br />
Bernard Lohr, 5/30/99)<br />
40. Hoot. This call may be a warning in response<br />
to the presence <strong>of</strong> potential predators.<br />
(Arizona, Greg Clark and Tim Price, 1/97)<br />
41. Male whistle call. Used by both sexes in<br />
mate contact, this call <strong>of</strong>ten precedes copulation.<br />
(Arizona, Frederick R. Gehlbach,<br />
6/21/98)<br />
42. Bark series. This was one <strong>of</strong> three series <strong>of</strong><br />
bark-like calls by a male near a nest. (Arizona,<br />
Bernard Lohr, 5/30/99)<br />
43. Female bark call transitioning into<br />
screech. <strong>Owls</strong> <strong>of</strong>ten direct barks at intruders<br />
near the nest. The barks may escalate<br />
into screeches as an owl’s level <strong>of</strong> agitation<br />
or aggression increases. (Arizona, Joseph T.<br />
Marshall Jr., ML 4506)<br />
44. Copulation sequence. The female whistle–calls<br />
prior to copulation, followed by the<br />
telegraphic trill from both sexes. Both sexes<br />
utter other calls during copulation. (Arizona,<br />
Frederick R. Gehlbach)<br />
Brian E. Small
Great Horned Owl Bubo virginianus<br />
Although the Great Horned Owl is our most<br />
widespread and recognized owl species, its<br />
wide repertoire <strong>of</strong> calls is little known and<br />
poorly understood. In addition to the familiar<br />
territorial hooting, Great Horned <strong>Owls</strong> utter<br />
a variety <strong>of</strong> barks, growls, screams, and chuckles<br />
that are difficult to characterize. Pair duets<br />
can be heard throughout <strong>North</strong> America at<br />
any time <strong>of</strong> the year but most frequently in<br />
late winter and early spring prior to egg laying.<br />
Males can always be distinguished from<br />
females by their deeper, more mellow voice.<br />
Considerable variation exists in the timing<br />
and number <strong>of</strong> hoots in a song. The fledgling<br />
begging call is another commonly heard<br />
call in the field that observers <strong>of</strong>ten do not<br />
recognize. It can be heard from late spring<br />
through fall.<br />
45. Territorial hooting or advertisement<br />
song. Often sung in duet, this call announces<br />
a territory and may serve to strengthen the<br />
pair bond. It is heard most commonly prior<br />
to egg-laying, <strong>of</strong>ten in the immediate vicinity<br />
<strong>of</strong> a chosen nest. When giving this hoot in<br />
song, the owl assumes a forward leaning posture<br />
with a cocked tail and an inflated throat.<br />
The number and timing <strong>of</strong> hoots varies<br />
among different individuals and populations.<br />
A double-hoot by the female is also audible.<br />
11<br />
This is probably the result <strong>of</strong> an interruption,<br />
rather than being a unique vocalization.<br />
(California, William R. Fish, ML 22874)<br />
46. Territorial hooting duet followed by<br />
copulation calls. Both birds, particularly the<br />
male, can be heard giving repeated hoots during<br />
copulation, followed by a squealing chitter<br />
call by the female. The interaction ends<br />
with a resumption <strong>of</strong> the duet. (New York,<br />
Gerrit Vyn, ML 128900)<br />
47. Female squawk with male territorial<br />
hoot in the distance. The squawk is a variable<br />
call sometimes used as a food solicitation call<br />
by the female early in the breeding season.<br />
The male also uses it. It is probably derived<br />
from the juvenile begging call. (Connecticut,<br />
Sean O’Brien)<br />
48. Female chitter call and squawk and male<br />
territorial hooting. (Maryland, Wilbur L.<br />
Hershberger, ML 94364)<br />
49. Male territorial hooting, female territorial<br />
hooting and squawks. (Arizona, Charles<br />
M. Bogert, ML 8366)<br />
50. Bark-like call. This may be a single wac<br />
call as heard on the following track. Captive.<br />
(Pennsylvania, Peter Paul Kellogg, ML 8359)<br />
51. Wac-wac call and billclap<br />
by a female during nest<br />
defense. Male hooting, which<br />
may functionally be a nestdefense<br />
or alarm call in this<br />
context, is audible in the background.<br />
(Manitoba, William<br />
W. H. Gunn, ML 59821)<br />
52. Squealing chitter call <strong>of</strong><br />
an injured bird. This call varies<br />
in intensity and generally expresses<br />
discomfort or agitation.<br />
Adults and juveniles use it in a<br />
variety <strong>of</strong> contexts. (New York,<br />
Peter Paul Kellogg, ML 8360)<br />
53. Fledgling begging<br />
call. (New York, David T.<br />
Spaulding, ML 8380)<br />
Gerrit Vyn
Snowy Owl Bubo scandiaca<br />
During the breeding season, Snowy <strong>Owls</strong><br />
are vocally active and use a wide repertoire <strong>of</strong><br />
vocalizations. This is especially true <strong>of</strong> males,<br />
who are more responsible for the defense <strong>of</strong><br />
territory and nest than are females. Little information<br />
is available on the vocal activity <strong>of</strong> this<br />
species outside <strong>of</strong> the nesting season, though it<br />
is clear they call infrequently. They are known<br />
to give several calls on their wintering grounds,<br />
particularly when defending winter feeding<br />
territories from other Snowy <strong>Owls</strong>. One call,<br />
<strong>of</strong>ten described as a scream, is probably a variation<br />
<strong>of</strong> the mewing whistle. It is given by both<br />
sexes and <strong>of</strong>ten by owls that are approached<br />
too closely by observers.<br />
54. Male territorial hoot or advertising song.<br />
Usually uttered in twos, variations <strong>of</strong> this<br />
vocalization probably serve as both song and<br />
call at times. When advertising a territory,<br />
males assume a forward bowing posture<br />
when giving this call. They also occasionally<br />
utter it in flight. Hooting volume is loudest<br />
during territorial defense. Females are known<br />
to hoot but rarely do so. (Sweden, Sture<br />
Palmer, ML 9435)<br />
55. Female bark call and bill snap. This alarm<br />
call is the most common call heard by human<br />
intruders at the nest. The piping squeals <strong>of</strong><br />
small chicks are also audible in this recording.<br />
12<br />
(Nunavut, Canada, Stewart D. MacDonald,<br />
CMN)<br />
56. Male bark call given in alarm at a nest.<br />
The begging squeals <strong>of</strong> chicks are also audible.<br />
(Nunavut, Canada, Stewart D. MacDonald,<br />
CMN)<br />
57. Mewing whistle <strong>of</strong> female. Primarily given<br />
by the female, this call is used in a variety <strong>of</strong><br />
situations, most commonly when soliciting<br />
food from the male at the nest. She also uses<br />
this call before and after being fed by the male,<br />
during distraction display, and in displacement<br />
coition. This call is also given in alarm when<br />
humans are near a nest. (Nunavut, Canada,<br />
Stewart D. MacDonald, CMN)<br />
58. Unidentified call. (Sweden, Sture Palmer,<br />
ML 9435)<br />
59. Unidentified call. (Sweden, Sture Palmer,<br />
ML 9434)<br />
60. Begging squeal and chitter call <strong>of</strong> fiveday-old<br />
chick. (Nunavut, Canada, Stewart D.<br />
MacDonald, CMN)<br />
61. Fledgling begging call and chitter. Young<br />
Snowy <strong>Owls</strong> leave the nest at an early age and<br />
disperse across the tundra around the nest. This<br />
call serves as a begging call and self-advertisement<br />
so adults can locate them for feeding.<br />
(Sweden, Sture Palmer, ML 9435)<br />
Gerrit Vyn
Spotted Owl (“<strong>North</strong>ern” subspecies) Strix occidentalis caurina<br />
Because <strong>of</strong> its status as an endangered species,<br />
the Spotted Owl has been studied more than<br />
any other <strong>North</strong> <strong>American</strong> owl. Vocally active,<br />
it commonly calls during the day if provoked to<br />
defend its territory. Otherwise, it is most vocal<br />
after sunset, early evening, and dawn. The sexes<br />
can usually be distinguished by voice pitch; the<br />
female’s vocalizations are higher. Both sexes use<br />
most vocalizations, but some <strong>of</strong> them are used<br />
more regularly by one sex. Most Spotted Owl<br />
hooting and contact vocalizations are used and<br />
intermixed during territorial encounters. These<br />
calls can vary significantly depending on the<br />
individual and circumstances. Playing recordings<br />
in the field <strong>of</strong> this federally protected endangered<br />
species is strongly discouraged.<br />
62. Male advertisement hooting or four-note<br />
location call. This is the most common hooting<br />
call. The male uses this primary song to<br />
announce a territory or when engaging in territorial<br />
disputes. Members <strong>of</strong> a pair also use it<br />
as a location call. A female contact whistle is<br />
audible in the background. (Oregon, Thomas<br />
G. Sander, ML 125367)<br />
63. Female advertisement hooting or fournote<br />
location call. (Oregon, Thomas G.<br />
Sander, ML 125377)<br />
64. Variation <strong>of</strong> four-note location call by a<br />
female. <strong>Owls</strong> commonly produce a three-note<br />
13<br />
location call when agitated. (Oregon, Ge<strong>of</strong>frey<br />
A. Keller, ML 56948)<br />
65. Variation <strong>of</strong> four-note location call by<br />
a male. In this example, the owl adds a note<br />
to the end <strong>of</strong> the call. (Oregon, Ge<strong>of</strong>frey A.<br />
Keller, ML 56949)<br />
66. Male series location call with female<br />
contact whistle in the background. This variable<br />
call consists <strong>of</strong> a series <strong>of</strong> hoots <strong>of</strong>ten ending<br />
with hoots similar to those ending the fournote<br />
location call. Males commonly use this<br />
call in territorial disputes but pairs also use it<br />
as a contact call. (Oregon, Thomas G. Sander,<br />
ML 125369)<br />
67. Female series location call consisting<br />
<strong>of</strong> a series <strong>of</strong> evenly spaced notes. (Oregon,<br />
Thomas G. Sander, ML 125377)<br />
68. Female series location call ending with an<br />
agitated contact whistle. (Oregon, Thomas G.<br />
Sander, ML 125375)<br />
69. Male series location call followed by female<br />
contact whistle. (Oregon, Ge<strong>of</strong>frey A.<br />
Keller, ML 56948)<br />
70. Contact whistle. This call is commonly<br />
heard and can vary greatly in intensity. Used<br />
more <strong>of</strong>ten by the female, this call advertises<br />
her location to her mate and <strong>of</strong>fspring.<br />
(Oregon, Thomas G. Sander, ML 125361)<br />
71. Female agitated contact whistle <strong>of</strong> varying<br />
intensities. (Oregon, Thomas G. Sander, ML<br />
125374)<br />
72. Female bark series. This variable call is primarily<br />
used by the female during high intensity<br />
territorial disputes. It is also used as a general contact<br />
call in some instances. (Oregon, Thomas G.<br />
Sander, ML 125373)<br />
73. Mellow female contact whistle and male nest<br />
call. The male uses the nest call when advertising<br />
potential nest sites to the female in the pre-nesting<br />
period, <strong>of</strong>ten calling continuously for several minutes.<br />
(California, Arthur A. Allen, ML 4544)<br />
74. Interaction between mates. A male utters a<br />
contact whistle in flight as he approaches a female,<br />
possibly delivering food. The female responds with<br />
a chitter call, followed by an agitated location call<br />
while the male begins giving the typical four-note<br />
location call. The female continues with whistle<br />
contact calls. The agitated location call is similar<br />
to the four-note location call but ends with an<br />
excited OW!. It is frequently heard when birds are<br />
excited during territorial encounters, sexual encounters,<br />
or food exchanges. (Oregon, Ge<strong>of</strong>frey A.<br />
Keller, ML 56948)<br />
75. Interaction by members <strong>of</strong> a pair. The male<br />
utters the series location call as the female flies<br />
in, giving contact whistles and chitter calls as she<br />
arrives. She then gives typical four-note location<br />
calls as the male departs, issuing agitated<br />
location calls. The female may have been<br />
soliciting a food transfer from the male.<br />
The chitter call is used during food transfers,<br />
copulation, and allopreening. It is also<br />
known to be used to express discomfort.<br />
(Oregon, Thomas G. Sander, ML 125368)<br />
Gerrit Vyn
Spotted Owl (“Mexican” subspecies) Strix occidentalis lucida<br />
The vocal behavior <strong>of</strong> the “Mexican”<br />
Spotted Owl is generally the same as that<br />
<strong>of</strong> the “<strong>North</strong>ern” Spotted Owl, though the<br />
Mexican subspecies is less inclined to vocalize<br />
during the day. Further descriptions and<br />
behavioral contexts <strong>of</strong> these calls can be found<br />
in the previous section about the northern<br />
subspecies. Playing recordings in the field <strong>of</strong><br />
this federally protected endangered species is<br />
strongly discouraged.<br />
76. Male advertisement hooting or four-note<br />
location call. (New Mexico, Wendy Kuntz,<br />
3/14/95)<br />
77. Male advertisement hooting or four-note<br />
location call. (New Mexico, Wendy Kuntz,<br />
6/19/96)<br />
78. Female advertisement hooting or fournote<br />
location call. A male is also audible in<br />
the background. (Arizona, Virginia Huber,<br />
ML 20869)<br />
79. Female agitated location call, male<br />
four-note location call, and female agitated<br />
contact whistle. The agitated location call is<br />
similar to the four-note but ends in an excited<br />
OW!. (Arizona, Virginia Huber, ML 20869)<br />
80. Female and male agitated location calls.<br />
In this example, the higher-pitched female<br />
14<br />
has omitted the first note. (New Mexico,<br />
Wendy Kuntz, 6/10/96)<br />
81. Male series location call with unevenly<br />
spaced notes. (New Mexico, Wendy Kuntz,<br />
7/16/96)<br />
82. Male series location call with evenly<br />
spaced notes. (New Mexico, Wendy Kuntz,<br />
4/5/96)<br />
83. Whistle contact calls <strong>of</strong> variable intensity<br />
by male and female. (New Mexico, Wendy<br />
Kuntz, 6/10/96)<br />
84. Agitated contact whistles by a pair. (New<br />
Mexico, Wendy Kuntz, 6/10/96)<br />
85. Bark series by male and female. The<br />
song <strong>of</strong> Canyon Wren (Catherpes mexicanus)<br />
is audible in the background. (New Mexico,<br />
Wendy Kuntz, 8/3/96)<br />
86. Various cooing calls between pair.<br />
Cooing calls are variable s<strong>of</strong>t calls <strong>of</strong>ten used<br />
when members <strong>of</strong> a pair are in close association,<br />
such as when roosting together or<br />
allopreening. (New Mexico, Wendy Kuntz,<br />
8/1/96)<br />
87. Variable contact-like calls and barks.<br />
(Arizona, Virginia Huber, ML 20870)<br />
88. Copulation sequence. (Arizona, Virginia<br />
Huber, ML 20869)<br />
89. Male prey delivery to female. Male gives<br />
four-note location call and agitated location<br />
call; female responds with chitter, squeals,<br />
and contact-like calls. (New Mexico, Wendy<br />
Kuntz, 5/7/96)<br />
90. Fledgling begging call. This call gradually<br />
develops into the adult contact call. (New<br />
Mexico, Wendy Kuntz, 6/23/96)<br />
Spotted Owl x Barred Owl hybrid<br />
Strix occidentalis x varia<br />
Unsustainable forestry practices in the Pacific<br />
<strong>North</strong>west have not only eliminated most <strong>of</strong><br />
the Spotted Owl’s old-growth forest habitat,<br />
but they have created corridors <strong>of</strong> younger<br />
forest habitat that the more adaptable Barred<br />
Owl has readily occupied. The fragmentation<br />
<strong>of</strong> Spotted Owl habitat and subsequent invasion<br />
<strong>of</strong> the Barred Owl into adjacent territory<br />
has put the Spotted Owl at great risk <strong>of</strong> being<br />
displaced by the more aggressive and closely<br />
related Barred Owl or <strong>of</strong> breeding with it. In<br />
many cases the two species have hybridized,<br />
producing viable <strong>of</strong>fspring, which further<br />
threaten the survival <strong>of</strong> the Spotted Owl, an<br />
endangered species.<br />
91. Advertisement hooting. (Washington,<br />
J. R. Fletcher, ML 93740)
Barred Owl Strix varia<br />
The Barred Owl is one <strong>of</strong> the most spectacular<br />
vocal performers <strong>of</strong> any <strong>North</strong> <strong>American</strong><br />
bird. Its familiar who cooks for you, who cooks<br />
for you all territorial announcement song, or<br />
two-phrase hoot, can be heard in many parts<br />
<strong>of</strong> the continent. Female calls can usually be<br />
distinguished from those <strong>of</strong> males by their<br />
higher pitch and more tremulous trailing<br />
notes. Pairs defending or announcing a territory<br />
frequently caterwaul, producing a variety<br />
<strong>of</strong> spectacular hoots, squeals, and quacks.<br />
These caterwauling bouts are strictly performed<br />
by mated pairs, usually to announce<br />
or defend a territory against other Barred<br />
<strong>Owls</strong>. The ascending hoot is another territorial<br />
hooting variation commonly heard when<br />
one pair confronts another. Barred <strong>Owls</strong><br />
are one <strong>of</strong> the few owl species that are commonly<br />
heard throughout the day in many<br />
parts <strong>of</strong> their range, particularly in southern<br />
swamplands where breeding densities are the<br />
highest.<br />
92. Female two-phrase hoot, ascending hoot,<br />
and pair caterwauling. (South Carolina,<br />
Ge<strong>of</strong>frey A. Keller, ML 105433)<br />
93. Pair caterwauling. (Florida, William R.<br />
Evans, ML 49708)<br />
94. Pair caterwauling with nestling begging<br />
15<br />
call in background. (Arkansas, Gerrit Vyn<br />
and Benjamin M. Clock, ML 128923)<br />
95. Female two-phrase hoot, followed by<br />
male ascending hoot, and a female ascending<br />
hoot variation. This variation is similar<br />
to that heard being given by an owl in flight<br />
on Track 100. (Arkansas, Gerrit Vyn and<br />
Benjamin M. Clock, ML 128930)<br />
96. Territorial dispute between two pairs. The<br />
proximate pair gives ascending hoots. Female<br />
two-phrase hoots and caterwauling are audible<br />
from a neighboring pair. (Arkansas, Gerrit Vyn<br />
and Benjamin M. Clock, ML 128925)<br />
97. Territorial dispute between two pairs.<br />
Ascending hoots, caterwauling, and a booming<br />
hoo-aw call are audible. (Arkansas, Gerrit<br />
Vyn and Benjamin Clock, ML 128926)<br />
98. Male hoo-aw call. This call may be used<br />
as a long distance contact call between mates.<br />
(Arkansas, Gerrit Vyn, ML 128927)<br />
99. Female hoo-aw call. Mates may use this<br />
call as a long distance contact call. (New York,<br />
Randolph S. Little, ML 106944)<br />
100. Female hoot variation. Females have<br />
been observed giving this call in flight while<br />
chasing other Barred <strong>Owls</strong> invading their territory.<br />
(Arkansas, Gerrit Vyn, ML 128931)<br />
101. Female solicitation call<br />
from nest cavity. When incubating<br />
eggs or brooding young<br />
chicks, females may utter this<br />
call repeatedly throughout the<br />
night as a food begging call<br />
to their mates. This call is also<br />
used as a contact call in some<br />
circumstances. (Arkansas,<br />
Gerrit Vyn, ML 128902)<br />
102. Distraction squeals and<br />
honk by a female in response to<br />
a large predator near the nest.<br />
This call is possibly being used in<br />
an injury-feigning display.<br />
(Arkansas, Gerrit Vyn and<br />
Benjamin M. Clock, ML<br />
128924)<br />
103. Fledgling begging call.<br />
(Florida, Robert C. Stein, ML<br />
4549)<br />
104. Fledgling begging call and<br />
male two-phrase hoot.<br />
(Maryland, Wilbur L.<br />
Hershberger, ML 79462)<br />
Gerrit Vyn
Great Gray Owl Strix nebulosa<br />
The Great Gray Owl has a large vocal repertoire<br />
during the breeding season. Both sexes use<br />
many <strong>of</strong> the same calls. Calls associated with<br />
defense <strong>of</strong> the nest and contact between pairs<br />
and juveniles are especially diverse and variable.<br />
Territorial hooting is most <strong>of</strong>ten heard during<br />
late winter and spring, but is also heard at<br />
other times <strong>of</strong> the year. The juvenile begging<br />
call is also frequently heard. It <strong>of</strong>ten sounds<br />
similar to that <strong>of</strong> the Great Horned Owl.<br />
105. Male territorial hooting. This call is<br />
primarily given by the male to promote pair<br />
formation, establish territory around a nest<br />
site, and in nest-showing. The female uncommonly<br />
gives a higher-pitched, harsher version<br />
with fewer notes, prior to egg laying. Captive.<br />
(Alaska, Leonard J. Peyton, ML 49945)<br />
106. Defensive or warning hooting. This call<br />
serves as a contact call between members <strong>of</strong> a<br />
breeding pair, <strong>of</strong>ten when intruders are near<br />
a nest site. It is sometimes given by the male<br />
when the female is <strong>of</strong>f the nest. (Oregon,<br />
David S. Herr, ML 48904)<br />
107. Defensive or warning hooting <strong>of</strong> an aggressive,<br />
highly agitated female. This call is <strong>of</strong><br />
a greater intensity than the previous call and directed<br />
towards a threat to the nest. It is given by<br />
both sexes. (Oregon, David S. Herr, ML 48904)<br />
16<br />
108. Male contact hoots announcing a prey<br />
delivery to the nest. A female g-wuk call<br />
is also audible. (Minnesota, Lang Elliott,<br />
6/14/93)<br />
109. Female contact call or whoop. The most<br />
common call given by the female, this vocalization<br />
is used for mate and family contact<br />
and as a food solicitation call from the nest. A<br />
red squirrel (Tamiasciurus hudsonicus) is also<br />
audible in this recording. (Oregon, David S.<br />
Herr, ML 47532)<br />
110. Female contact call or g-wuk. A variation<br />
<strong>of</strong> the call on Track 109. This female was<br />
soliciting food while in a nest. This call can<br />
vary greatly in intensity. Nestling begging<br />
calls are also audible. (Minnesota, Lang<br />
Elliott, 6/14/93)<br />
111. Chitter call <strong>of</strong> adult. This call is used<br />
in a variety <strong>of</strong> circumstances, most <strong>of</strong>ten by<br />
adults and juveniles during food transfers.<br />
It is also used to express discomfort, hunger,<br />
annoyance, and concern. Captive. (Alaska,<br />
Leonard J. Peyton, ML 49941)<br />
112. Distraction calls. A female uttered<br />
these calls during a distraction or injuryfeigning<br />
display near a nest. (Manitoba,<br />
Lang Elliott, 6/1/93)<br />
113. Agitated call by a female after a distraction<br />
display. (Manitoba, Lang Elliott, 6/1/93)<br />
114. Fledgling begging call interspersed by<br />
two exclamatory hoots that were probably<br />
given by the female. The owl uttered these<br />
hoots after it approached a vocalizing pine<br />
marten (Martes americana) which can be<br />
heard giving perturbed growls. Red squirrel<br />
(Tamiasciurus hudsonicus) is also audible.<br />
(Wyoming, Gregory F. Budney, ML 62945)<br />
115. Food exchange at nest site. First, a female<br />
utters the g-wuk food solicitation call<br />
and nestlings use chitter calls. A male flies in<br />
to a nearby tree, giving contact calls while the<br />
nestlings begin giving begging calls. As the<br />
male flies closer the intensity <strong>of</strong> the female’s<br />
g-wuk calls increases until she flies from the<br />
nest to receive prey from the male. At the<br />
time <strong>of</strong> food transfer, the male utters chitter<br />
calls and three deep hoots. The female returns<br />
to the nest. She and the nestlings utter chitter<br />
calls as food is transferred. The female also<br />
gives several s<strong>of</strong>ter squeals at the nest and<br />
during her return flight. (Minnesota, Lang<br />
Elliott, 6/14/93)<br />
116. Fledgling begging call. The howling <strong>of</strong><br />
coyote (Canis latrans) is also audible.<br />
(Wyoming, Gregory F. Budney, ML 62947)<br />
Gerrit Vyn
<strong>North</strong>ern Hawk Owl Surnia ulula<br />
A diurnal-crepuscular owl <strong>of</strong> the northern<br />
boreal forest, the <strong>North</strong>ern Hawk Owl is<br />
vocal and conspicuous during the breeding<br />
season. During that time, males sing from<br />
prominent perches within their territories,<br />
primarily around dawn and dusk. In a variety<br />
<strong>of</strong> contexts, both sexes utter various trilling<br />
calls that are similar to the male’s primary<br />
song. This species also has a wide repertoire <strong>of</strong><br />
alarm calls used around the nest. During the<br />
nonbreeding season, <strong>North</strong>ern Hawk <strong>Owls</strong><br />
are relatively quiet but do use several <strong>of</strong> the<br />
vocalizations described below.<br />
117. Male advertising song. This song may<br />
last up to 14 seconds and is <strong>of</strong>ten uttered in a<br />
display fight over the territory. The male also<br />
uses this song to advertise potential nest sites<br />
to the female. (Alaska, Leonard J. Peyton, ML<br />
49544)<br />
118. Trilling call. Both sexes use various<br />
trilling calls that are difficult to characterize.<br />
They use these calls in many contexts,<br />
including during nest disturbances. The male<br />
and female also utter trilling calls in duet during<br />
prey exchanges and copulation. (Alaska,<br />
Leonard J. Peyton, ML 49902)<br />
17<br />
119. Screeching call or screeee-yip followed<br />
by yelping call. Both sexes commonly issue<br />
these calls in alarm when an intruder is near a<br />
nest. They also use the screeching call widely<br />
in other contexts, including mate contact,<br />
food delivery, and female food solicitation.<br />
The yelping call is <strong>of</strong>ten uttered in flight, including<br />
during aerial attacks <strong>of</strong> potential nest<br />
predators. Nestling begging calls, similar to<br />
the adult screeching call, are audible in the<br />
background. (Alaska, Leonard J. Peyton, ML<br />
49954)<br />
120. Alarm squeals. An agitated owl near a<br />
nest uttered this call. It may be a distraction<br />
call. (Alaska, Leonard J. Peyton, ML 49910)<br />
121. Distress call. In winter, observers somtimes<br />
hear low-intensity versions <strong>of</strong> this call,<br />
given by alarmed owls. Captive. (Ontario,<br />
William W. H. Gunn, ML 61801)<br />
Gerrit Vyn
<strong>North</strong>ern Pygmy-Owl Glaucidium gnoma<br />
Heard throughout much <strong>of</strong> the coastal and<br />
mountain West, the diurnal-crepuscular<br />
<strong>North</strong>ern Pygmy-Owl sings most frequently<br />
near sunrise and sunset. It is also known to<br />
sing during the day. Songs <strong>of</strong> this species vary<br />
geographically and suggest that this species<br />
may be designated as several species in the<br />
future.<br />
[Note: The “chitter” calls described for<br />
<strong>North</strong>ern and Ferruginous pygmy-owls are<br />
not analogous to the chitter calls <strong>of</strong> other<br />
owl species. The use <strong>of</strong> the term “chitter” to<br />
describe pygmy-owl vocalizations may be the<br />
more appropriate usage. The term “discomfort<br />
call” may be more appropriate for describing<br />
the “chitter” in other owl species.]<br />
122. G.g. grinnelli. Male primary advertising<br />
or toot song. This is the common single-note<br />
song <strong>of</strong> the western coastal subspecies G.g.<br />
grinnelli. The primary song is <strong>of</strong>ten preceded<br />
by a trill which is not heard here. (Oregon,<br />
Ge<strong>of</strong>frey A. Keller, ML 105504)<br />
123. G.g. californicum. Male primary advertising<br />
or toot song. This is the common<br />
single-note song <strong>of</strong> the subspecies G.g. californicum.<br />
Found throughout much <strong>of</strong> the<br />
interior West, this subspecies is also known<br />
18<br />
to give a double-note song (not heard here).<br />
(Montana, Robert C. Faucett, ML 25653)<br />
124. G.g. gnoma. Male primary advertising<br />
or toot song. The subspecies G.g. gnoma,<br />
found in southeast Arizona and Mexico,<br />
typically sings a double-note song but will<br />
also sing a fast single-note song as heard here.<br />
(Arizona, Ge<strong>of</strong>frey A. Keller, ML 40576)<br />
125. G.g. gnoma. Male primary advertising<br />
or toot song. This is the typical double-note<br />
song <strong>of</strong> subspecies G.g. gnoma, or “Mountain<br />
Pygmy-Owl,” found in southeast Arizona and<br />
Mexico. (Arizona, L. Irby Davis, ML 9418)<br />
126. Male primary advertising song interspersed<br />
with prolonged chitter call. S<strong>of</strong>t<br />
female chitter calls can be heard which<br />
initiate the male’s use <strong>of</strong> the prolonged<br />
chitter. The behavioral context for this recording<br />
is unknown, although it seems<br />
to indicate a level <strong>of</strong> sexual excitement. It<br />
is probably analogous to the Ferruginous<br />
Pygmy-Owl sequence heard on Track 134.<br />
(Arizona, Frederick R. Gehlbach, 4/2/00)<br />
127. Female chitter call. (Arizona, Frederick<br />
R. Gehlbach, 4/2/00)<br />
128. Copulation calls. (Colorado, Robert<br />
Righter, 6/97)<br />
129. Food delivery at a nest.<br />
In this sequence the male<br />
gives several toots to announce<br />
a delivery. The female comes<br />
out <strong>of</strong> the nest, uttering chitter<br />
calls. She receives the<br />
food and returns to the nest<br />
cavity. (Arizona, Frederick R.<br />
Gehlbach, 2000)<br />
130. Female chitter call followed<br />
by an unknown call.<br />
The voice <strong>of</strong> a researcher is<br />
briefly heard at the end <strong>of</strong> this<br />
recording. (Arizona, Bernard<br />
Lohr, 6/6/00)<br />
131. Fledgling begging call.<br />
(Washington, Charles A.<br />
Sutherland, ML 9419)<br />
Jared Hobbs
Ferruginous Pygmy-Owl Glaucidium brasilianum<br />
A diurnal-crepuscular owl <strong>of</strong> extreme southern<br />
Arizona and Texas, the Ferruginous<br />
Pygmy-Owl is a common bird south <strong>of</strong> the<br />
border. It sings most frequently near dawn<br />
and dusk but also during the day and occasionally<br />
at night. Its song varies widely in<br />
volume, frequency, and duration. Both males<br />
and females use a version <strong>of</strong> the primary advertising<br />
song, with the females’ voices higher<br />
and sweeter. Researchers have proposed that<br />
this species should be split into two species,<br />
with the birds occurring in the United States<br />
referred to as Ridgway’s Pygmy-Owl<br />
(Glaucidium ridgwayi).<br />
132. Male primary advertising or territorial<br />
song. (Texas, Ge<strong>of</strong>frey A. Keller, ML 105563)<br />
133. Female primary advertising or territorial<br />
song. (Arizona, Greg Clark and Tim Price,<br />
2/02)<br />
134. Male primary advertising song interspersed<br />
with prolonged chitter calls. The<br />
female utters s<strong>of</strong>t chitter calls that seem to<br />
initiate the male’s use <strong>of</strong> the prolonged chitter.<br />
The behavioral context for this recording<br />
is unknown, although it seems to indicate<br />
sexual excitement. It is probably analogous to<br />
the <strong>North</strong>ern Pygmy-Owl sequence on Track<br />
125. (Mexico, Andres M. Sada, FMNH<br />
1019)<br />
19<br />
135. Female chitter call. The female uses<br />
this vocalization as a food solicitation call.<br />
She uses a shortened chitter as a contact call.<br />
It is derived from the fledgling begging call.<br />
(Texas, Glenn A. Proudfoot, 6/99)<br />
136. Female alarm or pee-weeet call. Females<br />
<strong>of</strong>ten use this call when human intruders are<br />
near the nest. (Texas, Glenn A. Proudfoot,<br />
6/99)<br />
137. Female aggression call. The owls utter<br />
this call in mild agitation when intruders<br />
approach the nest and in response to other<br />
Ferruginous Pygmy-Owl songs near the nest<br />
site. This call is commonly given by females,<br />
less <strong>of</strong>ten by males. (Texas, Glenn A.<br />
Proudfoot, 4/98)<br />
138. Female aggression call. (Arizona, Greg<br />
Clark and Tim Price, 2/02)<br />
139. Nestling distress call. (Texas, Glenn A.<br />
Proudfoot)<br />
140. Fledgling begging chitter. The calls <strong>of</strong><br />
Western Tanager (Piranga ludoviciana) are<br />
also prominent. (Texas, Glenn A. Proudfoot)<br />
Gerrit Vyn
Elf Owl Micrathene whitneyi<br />
<strong>North</strong> America’s smallest owl, this species<br />
is a common spring singer in parts <strong>of</strong> the<br />
Southwest. Although they are <strong>of</strong>ten associated<br />
with giant saguaro cacti, Elf Owl can be<br />
heard wherever suitable woodpecker cavities<br />
can be found for nesting. This includes many<br />
areas familiar to birders in southeast Arizona,<br />
where riparian sycamores and cottonwoods<br />
provide nest sites.<br />
141. Male chatter song and female station<br />
call. The male uses the chatter song for territorial<br />
advertisement and defense as well as to<br />
attract a mate. It is most <strong>of</strong>ten heard at dusk<br />
and dawn during the period <strong>of</strong> nest-site selection<br />
and pair formation in April and May.<br />
Both sexes use the station call as a contact call<br />
between mates and young. (Arizona, Ge<strong>of</strong>frey<br />
A. Keller, ML 40636)<br />
142. Prolonged male chatter song and<br />
female calls. Males utter this song from<br />
within a potential nest cavity or its immediate<br />
vicinity to lure the female to the cavity.<br />
Its intensity increases as the female responds<br />
or approaches. Various female calls can also<br />
be heard, including a cricket-like twitter in<br />
flight. (Arizona, Bernard Lohr, 5/7/01)<br />
143. Bark call and station call given by pair.<br />
The bark call is an alarm call or scolding call<br />
20<br />
directed at intruders, including humans, near<br />
the nest site. Used by both sexes, it varies in<br />
intensity depending on the owl’s level <strong>of</strong> agitation<br />
or alarm. A second bird can be heard<br />
giving the station call midway through the<br />
recording. (Arizona, Bernard Lohr, 6/6/00)<br />
144. Bark call. (Arizona, William W. H.<br />
Gunn, ML 59816)<br />
145. Copulation calls. (Arizona, J. David<br />
Ligon, ML 42361)<br />
146. Nestling begging rasp. (Arizona,<br />
Harriette Barker, ML 25169)<br />
Brian E. Small
Burrowing Owl Athene cunicularia<br />
Considered an accomplished vocalist, the<br />
Burrowing Owl is known to have a large repertoire<br />
<strong>of</strong> calls beyond those presented here.<br />
Its calls are well known, partly because <strong>of</strong> its<br />
diurnal activities and open country habitat,<br />
which have provided researchers with good<br />
opportunities for direct observation <strong>of</strong> vocalizing<br />
birds. Burrowing <strong>Owls</strong> are most active<br />
vocally in the spring, though courtship and<br />
alarm calls can be heard throughout the year.<br />
147. Male primary or courtship song. The<br />
male uses this song in the vicinity <strong>of</strong> the nest<br />
burrow. This territorial or advertisement song<br />
is accompanied by the bowing display.<br />
(California, Ge<strong>of</strong>frey A. Keller, ML 119481)<br />
148. Alarm chatter. Burrowing <strong>Owls</strong> use this<br />
call in nest defense or predator mobbing. It<br />
varies in intensity and duration. (California,<br />
Ge<strong>of</strong>frey A. Keller, ML 118856)<br />
149. Single alarm notes and alarm chatter.<br />
(Alberta, Albert Karvonen, ML 59807)<br />
150. Alarm chatter at burrow. (California,<br />
Gregory F. Budney, ML 126498)<br />
151. Nestling begging rasp and adult alarm<br />
chatter at burrow. (California, Gregory F.<br />
Budney, ML 126498)<br />
21<br />
152. Juvenile alarm call or rattlesnake rasp.<br />
When highly distressed, young owls utter<br />
this call from the nest burrow. It is believed<br />
to mimic the rattle <strong>of</strong> a rattlesnake (Crotalis<br />
spp.) to deter potential predators. Threatened<br />
adults sometimes produce a more convincing<br />
version. (Idaho, Jeffrey Rice, 6/22/04)<br />
Gerrit Vyn
Boreal Owl Aegolius funereus<br />
In recent years, the detection <strong>of</strong> singing and<br />
calling Boreal <strong>Owls</strong> has led to the discovery<br />
that Boreal <strong>Owls</strong> breed in many subalpine<br />
areas <strong>of</strong> the West as far south as New Mexico.<br />
Previously they were thought to breed only in<br />
the boreal forests. The male’s song is primarily<br />
heard in late winter and early spring prior<br />
to egg-laying. Unpaired males may continue<br />
singing into summer. Some <strong>of</strong> the Boreal<br />
Owl’s calls are very similar to those <strong>of</strong> the<br />
<strong>North</strong>ern Saw-whet Owl.<br />
153. Male primary or staccato song. This song<br />
serves as a long distance advertisement to<br />
potential mates and is usually given in the<br />
vicinity <strong>of</strong> potential nest cavities. Some listeners<br />
have confused this song with the winnowing <strong>of</strong><br />
Wilson’s Snipe (Gallinago delicata). (Alaska,<br />
Leonard J. Peyton, ML 49540)<br />
154. Male prolonged staccato song. The male<br />
uses this song to advertise a nest cavity when the<br />
female is present. The male may fly to and from<br />
a potential nest cavity and the female, giving<br />
the prolonged song in flight and from the cavity<br />
itself. Males <strong>of</strong>ten switch from the primary song<br />
to the prolonged song when the female appears.<br />
The song, which facilitates pair formation, is delivered<br />
s<strong>of</strong>tly compared with the primary song.<br />
(Minnesota, Steven G. Wilson, 6/89)<br />
22<br />
155. Male subdued staccato song or brief<br />
trill. Males utter a subdued version <strong>of</strong> the<br />
primary song in many instances. It is <strong>of</strong>ten<br />
heard prior to, after, or between long bouts <strong>of</strong><br />
the primary song. It is also sometimes used as<br />
the initial vocalization during a food delivery.<br />
(Minnesota, Steven G. Wilson, 6/89)<br />
156. Skiew call or screech. Both sexes use<br />
this variable call in a wide variety <strong>of</strong> contexts.<br />
Often delivered quite loudly, it commonly<br />
ends in a bill-clap. It is used year round and<br />
is <strong>of</strong>ten heard in response to broadcast <strong>of</strong> the<br />
primary song. It may serve as a contact call or<br />
a warning call, or it may suggest annoyance.<br />
(Minnesota, Steven G. Wilson, 6/89)<br />
157. Food delivery or moo-a call. The male<br />
uses this variable call to announce food deliveries<br />
to the nest or fledglings. Calls similar<br />
to this are also heard in response to broadcast<br />
<strong>of</strong> the primary song. (Minnesota, Steven G.<br />
Wilson, 6/89)<br />
158. Nestling peep and male food delivery<br />
call. (Minnesota, Steven G. Wilson, 6/89)<br />
159. Nestling chatter and female peep call<br />
from the nest. The female uses the peep call<br />
widely during the breeding season when soliciting<br />
food from the male or as a contact call.<br />
This call is derived from the juvenile begging<br />
call. (Alaska, Rosa Meehan,<br />
BLB 22369)<br />
160. Fledgling begging call<br />
or peep, male food delivery<br />
call, and a s<strong>of</strong>t skiew call.<br />
The winnowing <strong>of</strong> Wilson’s<br />
Snipe (Gallinago delicata)<br />
is also audible. (Minnesota,<br />
Steven G. Wilson, 6/89)<br />
Gerrit Vyn
<strong>North</strong>ern Saw-whet Owl Aegolius acadicus<br />
The diminutive <strong>North</strong>ern Saw-whet Owl is<br />
most conspicuous during the brief period from<br />
February through April when most male singing<br />
occurs. Throughout the rest <strong>of</strong> the year this<br />
species is heard infrequently or may be unrecognized<br />
by observers. The ksew call is a variable<br />
call that can be confused with the skiew<br />
<strong>of</strong> the Boreal Owl. This species is named for its<br />
“saw-whet” call, but there is much debate over<br />
which vocalization this refers to.<br />
161. Male advertising song. <strong>North</strong>ern<br />
Saw-whet <strong>Owls</strong> use this monotonous song in<br />
territorial establishment and mate attraction.<br />
The male sometimes sings it from prospective<br />
nest holes. The female sometimes sings a s<strong>of</strong>ter,<br />
less-consistent version. (Oregon, Ge<strong>of</strong>frey<br />
A. Keller, ML 42199)<br />
162. Advertising song. A young adult, possibly<br />
a female, may have uttered this sporadic<br />
version. (New York, Thomas Knight, ML<br />
89405)<br />
163. Whine-like call. (Utah, Kevin J. Colver,<br />
BLB 28001)<br />
164. Various calls recorded in fall. The first<br />
two series are ksew calls; the third series<br />
includes the high-pitched whine call and<br />
whine-like calls similar to those on Track 163.<br />
Both ksew and whine calls are <strong>of</strong>ten heard in<br />
23<br />
response to broadcast <strong>of</strong> the primary song.<br />
The final call is an unknown wail, possibly a<br />
whine in flight. (Pennsylvania, Scott<br />
Weidensaul, 10/26/04 & 11/9/04)<br />
165. Calls recorded in winter. (Pennsylvania,<br />
Steve Farbotnik, 1/7/79 & 3/3/78)<br />
166. Alarm call <strong>of</strong> male in response to an<br />
intruder near the nest. (Pennsylvania, Steve<br />
Farbotnik, 5/23/78)<br />
167. Unknown call. Captive. (New York,<br />
Robert W. Dickerman, ML 8330)<br />
168. Bill snap and twittering chitter.<br />
Captive. (Ontario, William W. H. Gunn, ML<br />
61810)<br />
169. Food deliveries at a nest. In the first<br />
sequence, nestling chitter calls and weak begging<br />
calls are audible, followed by the male<br />
delivery call, a series <strong>of</strong> toots announcing a<br />
food delivery at the nest. In the second delivery<br />
sequence, the difference between the begging<br />
calls <strong>of</strong> two nestlings at different levels <strong>of</strong><br />
development is apparent. (Pennsylvania, Steve<br />
Farbotnik, 6/21/78)<br />
Gerrit Vyn
Long-eared Owl Asio otus<br />
The diverse repertoire <strong>of</strong> the Long-eared<br />
Owl is primarily heard during the breeding<br />
season from late winter though spring. It<br />
uses a remarkable number <strong>of</strong> highly variable<br />
alarm and aggression calls that are most <strong>of</strong>ten<br />
heard around the nest. These vocalizations<br />
reflect a range <strong>of</strong> intensity and emotion in<br />
relation to many factors such as the type <strong>of</strong><br />
threat, stage <strong>of</strong> nest development, and previous<br />
experience <strong>of</strong> the adults. Calls tend to be<br />
most vigorous in the latter stages <strong>of</strong> breeding<br />
when the young are flightless but have left<br />
the nest. Long-eared <strong>Owls</strong> are considered to<br />
be quiet during the nonbreeding season but<br />
they are known to vocalize in the vicinity <strong>of</strong><br />
winter roosts, suggesting that further study is<br />
needed. This species is also known to perform<br />
elaborate display flights.<br />
170. Male advertising song. Males use this<br />
deep hooting song to attract a mate and<br />
announce a territory. Male hooting is also<br />
commonly used in alarm and is one <strong>of</strong> the<br />
first calls researchers hear when approaching<br />
a nest. (Washington, David S. Herr, ML<br />
49057)<br />
171. Female nest call. The female uses this<br />
variable call at the nest or its immediate vicinity.<br />
It may be a food solicitation call. It<br />
is heard in early spring during the period <strong>of</strong><br />
24<br />
nest selection and through the early portion<br />
<strong>of</strong> nesting. It is <strong>of</strong>ten uttered in response to<br />
the male’s song or wing-clapping. (California,<br />
Thomas G. Sander, ML 110984)<br />
172. Female nest call. This example has a<br />
sighing element. (New York, Lang Elliott,<br />
3/22/92)<br />
173. Pair duet with the female nest call in<br />
the foreground. The male’s advertising song<br />
is more distant. (Washington, David S. Herr,<br />
ML 48901)<br />
174. Male wing-clap and female nest call.<br />
Females <strong>of</strong>ten use the nest call in response<br />
to the male’s wing-clap display flight. Males<br />
perform an erratic buoyant flight through the<br />
trees, interspersed with wing-claps below the<br />
body. These flights sometimes circle a newly<br />
selected nest site as the female responds from<br />
the nest with the nest call. Males also wingclap<br />
in nest defense. (Washington, David S.<br />
Herr, ML 47531)<br />
175. Male barking alarm call at a nest. This<br />
is the most common call used in alarm at the<br />
nest. This call is also known to express other<br />
types <strong>of</strong> agitation. (New Jersey, George B.<br />
Reynard, ML 8344)<br />
176. Female barking alarm call<br />
at a nest. (New Jersey, George B.<br />
Reynard, ML 8350)<br />
177. Alarm call at a nest. (New<br />
Jersey, George B. Reynard, ML<br />
8350)<br />
178. High intensity alarm call and<br />
bill-clap at a nest. (Manitoba, Lang<br />
Elliott, 6/13/93)<br />
179. Alarm call given in flight near<br />
a threatened nest. (George B.<br />
Reynard, ML 8350)<br />
180. Low intensity alarm call and<br />
bill-clap at a nest. These vocalizations<br />
are <strong>of</strong>ten accompanied by the<br />
forward-threat posture. (New Jersey,<br />
George B. Reynard, ML 8350)<br />
181. Distraction squeal by a highly<br />
alarmed bird at a nest. (Manitoba,<br />
Lang Elliott, 6/13/93)<br />
182. Bill-clap and hiss by an<br />
alarmed bird at a nest. (New Jersey,<br />
George B. Reynard, ML 8350)<br />
183. Fledgling begging call.<br />
(Vermont, Matthew D. Medler, ML<br />
126495)<br />
Gerrit Vyn
Short-eared Owl Asio flammeus<br />
The Short-eared Owl’s reputation as a quiet<br />
bird is undeserved. Even in winter, birds commonly<br />
vocalize when interacting and foraging.<br />
The male’s courtship flight, wing-clapping,<br />
and hooting during courtship, are also contrary<br />
to this reputation. Males have lower<br />
pitched voices than females, but this difference<br />
is not as pronounced as it is in most other owl<br />
species. Bark-like calls are used frequently and<br />
are quite variable, probably representing several<br />
unique vocalizations. Further research is<br />
needed to classify these calls and describe their<br />
behavioral contexts.<br />
184. Male primary song and wing-clap. This<br />
hooting song is usually heard in late winter<br />
and early spring on the breeding grounds.<br />
Males generally utter it during their courtship<br />
flights, <strong>of</strong>ten as they hover into the wind.<br />
Perched birds also use it, especially after a<br />
courtship flight. The elaborate courtship<br />
flight includes many rapid series <strong>of</strong> wing-claps<br />
beneath the body, as heard here. Birds may<br />
also wing-clap in nest defense and during<br />
territorial skirmishes. (Alaska, Brian J.<br />
McCaffery, ML 50052)<br />
185. Bark call by an owl in flight. (Oregon,<br />
David S. Herr, ML 45302)<br />
25<br />
186. Bark calls by a flying owl in response to<br />
intruders near a nest. (Manitoba, Arthur A.<br />
Allen and Peter Paul Kellogg, ML 22671)<br />
187. Bark call by a perched owl near a communal<br />
winter roost. (New York, Gerrit Vyn,<br />
ML 128922)<br />
188. Bark call in flight during antagonistic<br />
encounters between hunting birds in winter.<br />
These calls were made by a bird harassing<br />
both flying and perched individuals. (New<br />
York, Gerrit Vyn, ML 128922)<br />
189. Female distraction call and bill-clap in<br />
response to a nest intruder. In cases <strong>of</strong> high<br />
intensity alarm at the nest, both sexes utter various<br />
squealing calls during an injury-feigning or<br />
distraction display. (Manitoba, Arthur A. Allen<br />
and Peter Paul Kellogg, ML 22672, 22674)<br />
190. Fledgling begging call. Captive.<br />
(Manitoba, Richard J. Clark, ML 22683)<br />
191. Fledgling chitter call. Captive.<br />
(Manitoba, Richard J. Clark, ML 22683)<br />
Gerrit Vyn
Extralimital Species<br />
Mottled Owl Strix virgata<br />
This widespread and common Latin<br />
<strong>American</strong> species finds its northern limits in<br />
Mexico about 80 miles south <strong>of</strong> the Texas<br />
border. It has been recorded once in the<br />
United States, near Bentsen-Rio Grande<br />
Valley State Park, where a bird was found<br />
dead on a roadside. Like the Barred Owl, the<br />
Mottled Owl is known to be highly vocal and<br />
produces a wide variety <strong>of</strong> sounds.<br />
192. Male advertising song or territorial<br />
hooting. (Chiapas, Mexico, Curtis A.<br />
Marantz, ML 127206)<br />
26<br />
Stygian Owl Asio stygius<br />
The Stygian Owl is an elusive species with<br />
a patchy distribution from north-central<br />
Mexico to northern Argentina and parts <strong>of</strong><br />
the Caribbean. It has been seen on two occasions<br />
at Bentsen-Rio Grande Valley State Park<br />
in southern Texas. Like the similar Longeared<br />
Owl, this species is known to produce a<br />
wing-clap in display flight.<br />
193. Male advertising song or hoot with female<br />
call in response. This sequence may be<br />
analogous to the male advertising song and<br />
female nest call duet <strong>of</strong> Long-eared Owl (Track<br />
173). Common Paraque (Nyctidromus albicollis)<br />
is vocalizing prominently in the background.<br />
(Belize, George B. Reynard, 3/21/75)<br />
Alphabetized Species List And Vocalization Types<br />
Species are listed alphabetically. Vocalizations are preceded by track number. They are listed in the<br />
order in which they appear on the guide.<br />
Owl, Barn<br />
2 Territorial scream<br />
3 Territorial scream<br />
3 Territorial scream, wing-clap<br />
4 Warning scream<br />
5 Distress call<br />
7 Sustained defensive hiss, bill-clap,<br />
warning scream<br />
8 Sustained defensive hiss<br />
9 Kleak-kleak call<br />
10 Calls at nest<br />
11 Fledgling mobbing call<br />
12 Fledgling begging snore<br />
Owl, Barred<br />
92 Female two-phrase hoot, ascending<br />
hoot, caterwaul<br />
93 Pair caterwauling<br />
94 Pair caterwauling<br />
95 Female two-phrase hoot, male<br />
ascending hoot, female hoot variation<br />
96 Ascending hoot, two-phrase hoot,<br />
caterwaul<br />
97 Ascending hoot, caterwaul, hoo-aw<br />
98 Male hoo-aw<br />
99 Female hoo-aw<br />
100 Female hoot variation<br />
101 Female solicitation call<br />
102 Distraction squeals and honk<br />
103 Fledgling begging call<br />
104 Fledgling begging call, male<br />
two-phrase hoot<br />
Owl, Barred x Spotted<br />
91 Advertisement hooting<br />
Owl, Boreal<br />
153 Male staccato song<br />
154 Male prolonged staccato song<br />
155 Male subdued staccato song<br />
156 Skiew call<br />
157 Male food delivery call<br />
158 Nestling peep, male food delivery call<br />
159 Nestling chatter, female peep<br />
160 Fledgling begging call, male food<br />
delivery call, skiew call<br />
Owl, Burrowing<br />
147 Male primary song<br />
148 Alarm chatter<br />
149 Alarm notes, alarm chatter<br />
150 Alarm chatter<br />
151 Nestling begging rasp, adult<br />
alarm chatter<br />
152 Juvenile rattlesnake rasp<br />
Owl, Elf<br />
141 Male chatter song, female station call<br />
142 Prolonged male chatter song,<br />
female call<br />
143 Bark call, station call<br />
144 Bark call<br />
145 Copulation<br />
146 Nestling begging rasp
Owl, Flammulated<br />
13 Male territorial hoot<br />
14 Female hoot<br />
15 Nestling begging snore, adult food<br />
delivery hoot<br />
16 Female bark, nestling begging snore<br />
17 Male bark<br />
18 Female moan<br />
19 Distress shriek, bill-clap<br />
Owl, Great Gray<br />
105 Male territorial hoot<br />
106 Defensive hoot<br />
107 Defensive hoot<br />
108 Male contact hoot<br />
109 Female contact call<br />
110 Female contact call, nestling<br />
begging call<br />
111 Chitter call<br />
112 Distraction calls<br />
113 Agitated call<br />
114 Fledgling begging call, hoot<br />
115 Food exchange at nest<br />
116 Fledgling begging call<br />
Owl, Great Horned<br />
45 Territorial hooting duet<br />
46 Territorial hooting duet, copulation<br />
47 Female squawk, male territorial hoot<br />
48 Female chitter call, squawk,<br />
male territorial hoot<br />
49 Male territorial hoot, female<br />
territorial hoot, squawk<br />
50 Bark-like call<br />
27<br />
51 Female wac-wac call, bill-clap,<br />
male hoot<br />
52 Chitter call<br />
53 Fledgling begging call<br />
Owl, Long-eared<br />
170 Male advertising hoot<br />
171 Female nest call<br />
172 Female nest call<br />
173 Female nest call, male<br />
advertising hoot<br />
174 Male wing-clap, female nest call<br />
175 Male bark<br />
176 Female bark<br />
177 Alarm call<br />
178 High intensity alarm call, bill-clap<br />
179 Alarm call in flight<br />
180 Low intensity alarm call, bill-clap<br />
181 Distraction squeal<br />
182 Bill-clap, hiss<br />
183 Fledgling begging call<br />
Owl, Mottled<br />
192 Male territorial hoot<br />
Owl, <strong>North</strong>ern Hawk<br />
117 Male advertising song<br />
118 Trilling call<br />
119 Screeching call, yelping call<br />
120 Alarm squeals<br />
121 Distress call<br />
Owl, <strong>North</strong>ern Saw-whet<br />
161 Male advertising song<br />
162 Advertising song<br />
163 Whine-like call<br />
164 Ksew call, whine call, whine-like call<br />
165 Calls<br />
166 Male alarm call<br />
167 Unknown call<br />
168 Bill snap, chitter call<br />
169 Food deliveries at nest<br />
Owl, Short-eared<br />
184 Male hoot, wing-clap<br />
185 Bark call<br />
186 Bark call<br />
187 Bark call<br />
188 Bark call<br />
189 Female distraction call, bill-clap<br />
190 Fledgling begging call<br />
191 Fledgling chitter call<br />
Owl, Snowy<br />
54 Male territorial hoot<br />
55 Female bark call, bill snap<br />
56 Male bark call<br />
57 Female mewing whistle<br />
58 Unidentified call<br />
59 Unidentified call<br />
60 Nestling begging squeal, chitter call<br />
61 Fledgling begging call, chitter<br />
Owl, Spotted (“Mexican”)<br />
76 Male four-note location call<br />
77 Male four-note location call<br />
78 Female four-note location call<br />
79 Female agitated location call,<br />
male four-note location call, female<br />
agitated contact whistle<br />
80 Agitated location call<br />
81 Male series location call<br />
82 Male series location call<br />
83 Whistle contact call<br />
84 Agitated contact whistle<br />
85 Bark series<br />
86 Cooing call<br />
87 Contact-like call, bark<br />
88 Copulation<br />
89 Prey delivery<br />
90 Fledgling begging call<br />
Owl, Spotted (“<strong>North</strong>ern”)<br />
62 Male four-note location call<br />
63 Female four-note location call<br />
64 Female three-note location call<br />
65 Male five-note location call<br />
66 Male series location call, female<br />
contact whistle<br />
67 Female series location call<br />
68 Female series location call, agitated<br />
contact whistle<br />
69 Male series location call, female<br />
contact whistle<br />
70 Contact whistle<br />
71 Female agitated contact whistle<br />
72 Female bark series<br />
73 Female contact whistle, male nest call<br />
74 Pair interaction<br />
75 Pair interaction<br />
Owl, Stygian<br />
193 Male advertising hoot, female call<br />
Pygmy-Owl, Ferruginous<br />
132 Male primary advertising song
133 Female primary advertising song<br />
134 Male primary advertising song,<br />
prolonged chitter call, female<br />
chitter call<br />
135 Female chitter call<br />
136 Female alarm call<br />
137 Female aggression call<br />
138 Female aggression call<br />
139 Nestling distress call<br />
140 Fledgling begging chitter<br />
Pygmy-Owl, <strong>North</strong>ern<br />
122 Male toot song (G.g. grinnelli)<br />
123 Male toot song (G.g. californicum)<br />
124 Male toot song (G.g. gnoma)<br />
125 Male double-note toot song<br />
(G.g. gnoma)<br />
126 Male toot song, prolonged chitter<br />
call, female chitter call<br />
127 Female chitter call<br />
128 Copulation<br />
129 Food delivery at nest<br />
130 Female chitter call, unknown call<br />
131 Fledgling begging call<br />
Screech-Owl, Eastern<br />
25 Descending trill, monotonic trill<br />
26 Descending trill<br />
27 Monotonic trill<br />
28 Monotonic trill<br />
29 Monotonic trill<br />
30 Screech call, bill-clap<br />
31 Screech call, chuckle rattle<br />
32 Bark call<br />
28<br />
33 Nestling begging rasp, chitter call,<br />
chuckle rattle<br />
34 Food delivery at nest<br />
Screech-Owl, Western<br />
20 Bouncing ball song, double trill song<br />
21 Double trill song, bouncing ball song<br />
22 Agitated bark, bill-clap<br />
23 Te-te-do call, agitated double trill<br />
24 Female solicitation call<br />
Screech-Owl, Whiskered<br />
35 Male short trill<br />
36 Male short trill<br />
37 Male telegraphic trill<br />
38 Telegraphic trill, squeal<br />
39 Male prolonged trill<br />
40 Hoot<br />
41 Male whistle call<br />
42 Bark series<br />
43 Female bark call, screech<br />
44 Copulation<br />
PROduceR / StudIO engIneeR / SOund SelectOR / text AuthOR<br />
Gerrit Vyn<br />
cO-PROduceR<br />
Gregory F. Budney<br />
PROductIOn MAnAgeR<br />
Mary S. Guthrie<br />
SuPeRvISIng engIneeR<br />
Robert W. Grotke<br />
dIgItAl IMAgeS<br />
Diane McAllister, Herbert Clarke, Herbert G. Fischer, Diana LeVasseur, Jim Milmoe,<br />
Cameron Rognan, Nick Saunders, Dominic Sherony, Ted Shroeder, Peter R. Stettenheim,<br />
Jim Weaver and US Fish and Wildlife.<br />
Front and back cover photographs courtesy <strong>of</strong> Gerrit Vyn<br />
www.gerritvynphoto.com<br />
© 2006 Cornell Lab <strong>of</strong> Ornithology