ISBN 0-938027-66-2

Voices of North American OwlsThis comprehensive 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, appreci-ate, 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 vocal-izations 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

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 appear-ance. 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 re-searchers 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 compi-lation 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

Introduction

“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 repre-sent the stark twilight and unsatisfied thoughts which all have.”

Henry David Thoreau, Walden

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for owls and the importance of conserv-ing 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 hatch-ing, young Barred Owls give specific calls that communicate hunger to their parents and stimulate the adults to feed them (Track 103). Though the 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. (Track 100).

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 ag-gression. 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 vocaliza-tion 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 com-municates 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 vocaliza-tions 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 Audio Guide

Some selections on this guide were made strictly to illustrate particular vocaliza-tions, some to illustrate behavioral sequences, and others for sheer listening pleasure. Therefore the length and qual-ity 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 identifica-tion of many previously described calls and associated behavior problematic. Additionally, observing behavior as-sociated 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 vocal-ization a conservative interpretation of the available literature. Behavioral

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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. Track 1 contains a sample track of the guide.

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 guide, 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 His-tory (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 record-ings 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 addi-tions. Our sincerest thanks also to those who provided their expertise, time, and knowledge in reviewing portions of the species text and associated record-

ings: 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. Ev-

ans, 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, Geof-frey 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, Da-vid T. Spaulding, Sally Spofford, Robert C. Stein, Charles A. Sutherland, Gerrit Vyn, Scott Weidensaul, and Steven G. Wilson.

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Resources And Bibliography

The Birds of North America Online www.bna.birds.cornell.edu

Johnsgard, P. A. North American Owls: Biology and Natural History, 2nd edition. Washington, D.C.: Smithsonian Institu-tion; 2002.

Duncan, J. R. Owls of the World: Their Lives, Behavior, and Survival. Buffalo, NY: Firefly Books; 2003.

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 organiza-tion dedicated to owl research, conservation, and public education www.owlinstitute.org

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 www.theowlfoundation.ca

A Note To Recordists And Researchers

This guide 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 col-lection 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 visit our website to obtain source recordings. Our complete audio catalogue is available for listening and spectrographic anaysis at www.macaulaylibrary.org. The preservation and study of acoustic communication recordings of birds and other animals is the focus of the Macaulay Library at the Cornell Lab 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 Lab of Ornithology, please contact us.

Macaulay LibraryCornell Lab of Ornithology159 Sapsucker Woods RoadIthaca, NY 14850telephone: (607) 254-2404email: macaulaylibrary@cornell.eduwebsite: www.macaulaylibrary.org

Interpreting and conserving the earth’s biological diversity through research, education, and citizen science focused on birds

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The Barn Owl’s screams, pale ghostlike ap-pearance, and inhabitation of abandoned buildings, farms, and church belfries have probably contributed to superstitions about owls around the world. Barn Owls are vo-cally 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 grad-ing into each other. This makes it difficult to distinguish between subtly different calls, de-scribe 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.

2. 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)3. Territorial scream or advertising call.Described as shrrreeeeee, this call was probably made by a female. (Washington, David S. Herr, ML 50540)4. 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)

5. Warning scream, or alarm call of an adult. (Washington, David S. Herr, ML 50541) 6. 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)7. Sustained defensive hiss, bill-clap, and warning scream by captive advanced nest-lings. (New York, Sally Spofford, ML 8325) 8. Sustained defensive hiss by an adult. Owls often use this call when threatened or cor-nered, often accompanied by threat postures. If the danger persists, this call often grades into the distress call. These calls and the relat-ed postures are intended to intimidate preda-tors. Captive. (New York, Peter Paul Kellogg, ML 8319)9. Kleak-kleak call. The male commonly ut-ters this call in flight during nesting, often to announce food deliveries to the nest. (California, Robert C. Stein, ML 8322)10. 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 record-ing. A male may have been delivering food to an incubating female. (California, William R. Fish, ML 22812)

11. Fledgling mobbing call.Owls usually direct this scold-ing call toward terrestrial pred-ators, including humans. A second fledgling is audible, ut-tering begging snores. (Florida, Gerrit Vyn, ML 104569)12. 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)

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Barn Owl Tyto alba

Juan Baham

on

Track Number/Description

VOICES OF NORTH AMERICAN OWLS TRACK LIST

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Although the Flammulated Owl is one or our smallest owls, its hoot is one of the lowest-frequency owl songs in North America. The male’s hoot also has a ventriloquial quality, making it difficult to observe this small, cryp-tically 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 interme-diate calls are commonly described as barks and moans. 13. 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)14. Female hoot. A female uttered these hoots as she solicited courtship feedings from a male. (New Mexico, D. Archibald McCallum, 5/12/81)

15. Begging snores of nestlings and low am-plitude 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)16. Bark by an alarmed female, and nestling begging snore. Barking can escalate into a va-riety of screams and shrieks depending on an owl’s level of agitation or aggression. (Oregon, David S. Herr, ML 50536)17. Male bark in response to a human intruder near a pair. (New Mexico, D. Archibald McCallum, 4/29/03)18. Female moan. (New Mexico, D. Archibald McCallum, 7/6/83)19. Distress shriek and bill-clap of an injured bird. (Texas, Greg Lasley, FMNH 1288)

Flammulated Owl Otus flammeolus

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Western Screech-Owl Megascops kennicotti

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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 egg-laying. 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 vocal-izations, with the female having a noticeably higher voice. 20. Pair duet. Bouncing ball and double trill songs are given by both sexes. The female’s voice is higher pitched. Various unidenti-fied calls are audible during an interaction between a pair at the end of the recording. Elf Owl (Micrathene whitneyi) barks are also au-dible during the duet. (Arizona, Geoffrey A. Keller, ML 109017)21. Double trill song followed by bounc-ing 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)22. Agitated bark and bill-clap. (Washington, David S. Herr, ML 63001)

23. Te-te-do call progressing into agitated double trill. This call requires further study but is known to be given by owls when con-fronted 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)24. Female solicitation call or begging whin-ny. 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)

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Eastern Screech-Owl Megascops asio

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The Eastern Screech-Owl uses its descend-ing trill song, or whinny, mainly for territo-rial 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 fam-ily bonds and is primarily used during the courtship and pre-nesting period from mid-winter 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 varia-tion in both song types between individuals may serve in sexual and individual recogni-tion. Both sexes utter all vocalizations, with the male’s voice noticeably lower. 25. 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 de-livered song. Captive. (New York, Hugh P. McIsaac, ML 20427)

26. Descending trill during territorial de-fense. (Maryland, Wilbur L. Hershberger, ML 100704)27. Monotonic trill with descending trill in the background. (Maryland, Wilbur L. Hershberger, ML 107446)28. Monotonic trill with evenly spaced notes. Chuck-will’s-widow (Caprimulgus carolinen-sis) is prominently audible in the background. (Florida, Geoffrey A. Keller, ML 105733) 29. Monotonic trill of shorter duration by M.a. mccallii in South Texas. (Texas, Matthew D. Medler, ML 87462)30. Screech calls and bill-claps by agitated pair. (Maryland, Wilbur L. Hershberger, ML 94524)31. Screech and chuckle rattle. Both nestlings and adults utter the chuckle rattle, generally signifying annoyance. Captive. (New York, Hugh P. McIsaac, ML 20428)32. Bark call. Captive. (New York, Hugh P. McIsaac, ML 20428) 33. Begging rasps, chitter calls, and chuckle rattle of nestlings. (New York, Arthur A. Allen, ML 4451, 4452, 4451, 39893)34. Food delivery at a nest. (New York, Arthur A. Allen, ML 39890)

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Whiskered Screech-Owl Otus trichopsis

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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 syn-copated song often sung in duet by pairs. It is associated with pair contact, defense of ter-ritory, 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.35. Male short trill. The male uses this song in territorial defense and when advertis-ing prospective nest cavities. (New Mexico, Curtis A. Marantz, ML 112621)36. Male short trill. (Arizona, Geoffrey A. Keller, ML 40588) 37. Telegraphic trill of male. (Arizona, Greg Clark, 1/97)38. 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)

39. 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)40. Hoot. This call may be a warning in re-sponse to the presence of potential predators. (Arizona, Greg Clark and Tim Price, 1/97) 41. Male whistle call. Used by both sexes in mate contact, this call often precedes copu-lation. (Arizona, Frederick R. Gehlbach, 6/21/98)42. Bark series. This was one of three series of bark-like calls by a male near a nest. (Arizona, Bernard Lohr, 5/30/99)43. Female bark call transitioning into screech. Owls often direct barks at intrud-ers 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)44. Copulation sequence. The female whis-tle–calls prior to copulation, followed by the telegraphic trill from both sexes. Both sexes utter other calls during copulation. (Arizona, Frederick R. Gehlbach)

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Great Horned Owl Bubo virginianus

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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 chuck-les 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 lay-ing. 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 fledg-ling 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.45. 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 pos-ture 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.

This is probably the result of an interrup-tion, rather than being a unique vocalization. (California, William R. Fish, ML 22874)46. Territorial hooting duet followed by copulation calls. Both birds, particularly the male, can be heard giving repeated hoots dur-ing copulation, followed by a squealing chit-ter call by the female. The interaction ends with a resumption of the duet. (New York, Gerrit Vyn, ML 128900) 47. 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)48. Female chitter call and squawk and male territorial hooting. (Maryland, Wilbur L. Hershberger, ML 94364)49. Male territorial hooting, female territo-rial hooting and squawks. (Arizona, Charles M. Bogert, ML 8366)50. Bark-like call. This may be a single wac call as heard on the following track. Captive. (Pennsylvania, Peter Paul Kellogg, ML 8359)

51. Wac-wac call and bill-clap by a female during nest defense. Male hooting, which may functionally be a nest-defense or alarm call in this context, is audible in the back-ground. (Manitoba, William W. H. Gunn, ML 59821)52. Squealing chitter call of an injured bird. This call varies in intensity and generally ex-presses discomfort or agitation. Adults and juveniles use it in a variety of contexts. (New York, Peter Paul Kellogg, ML 8360)53. Fledgling begging call. (New York, David T. Spaulding, ML 8380)

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Snowy Owl Bubo scandiaca

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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 infor-mation 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 varia-tion of the mewing whistle. It is given by both sexes and often by owls that are approached too closely by observers. 54. 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)55. 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 are also audible in this recording.

(Nunavut, Canada, Stewart D. MacDonald, CMN)56. Male bark call given in alarm at a nest. The begging squeals of chicks are also audible. (Nunavut, Canada, Stewart D. MacDonald, CMN)57. 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)58. Unidentified call. (Sweden, Sture Palmer, ML 9435)59. Unidentified call. (Sweden, Sture Palmer, ML 9434)60. Begging squeal and chitter call of five-day-old chick. (Nunavut, Canada, Stewart D. MacDonald, CMN)61. 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-advertise-ment so adults can locate them for feeding. (Sweden, Sture Palmer, ML 9435)

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Spotted Owl (“Northern” subspecies) Strix occidentalis caurina

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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 endan-gered species is strongly discouraged. 62. Male advertisement hooting or four-note location call. This is the most common hoot-ing call. The male uses this primary song to announce a territory or when engaging in ter-ritorial 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)63. Female advertisement hooting or four-note location call. (Oregon, Thomas G. Sander, ML 125377)64. Variation of four-note location call by a female. Owls commonly produce a three-note

location call when agitated. (Oregon, Geoffrey A. Keller, ML 56948)65. 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)66. Male series location call with female contact whistle in the background. This vari-able call consists of a series of hoots often end-ing with hoots similar to those ending the four-note 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)67. Female series location call consisting of a series of evenly spaced notes. (Oregon, Thomas G. Sander, ML 125377)68. Female series location call ending with an agitated contact whistle. (Oregon, Thomas G. Sander, ML 125375)69. Male series location call followed by fe-male contact whistle. (Oregon, Geoffrey A. Keller, ML 56948)70. 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)

71. Female agitated contact whistle of varying intensities. (Oregon, Thomas G. Sander, ML 125374)72. Female bark series. This variable call is pri-marily used by the female during high intensity territorial disputes. It is also used as a general con-tact call in some instances. (Oregon, Thomas G. Sander, ML 125373)73. 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 min-utes. (California, Arthur A. Allen, ML 4544)74. 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 en-counters, or food exchanges. (Oregon, Geoffrey A. Keller, ML 56948)75. 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

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 trans-fers, copulation, and allopreening. It is also known to be used to express discomfort. (Oregon, Thomas G. Sander, ML 125368)

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Spotted Owl (“Mexican” subspecies) Strix occidentalis lucida

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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 vocal-ize 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.76. Male advertisement hooting or four-note location call. (New Mexico, Wendy Kuntz, 3/14/95)77. Male advertisement hooting or four-note location call. (New Mexico, Wendy Kuntz, 6/19/96)78. Female advertisement hooting or four-note location call. A male is also audible in the background. (Arizona, Virginia Huber, ML 20869)79. 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)80. Female and male agitated location calls. In this example, the higher-pitched female

has omitted the first note. (New Mexico, Wendy Kuntz, 6/10/96)81. Male series location call with unevenly spaced notes. (New Mexico, Wendy Kuntz, 7/16/96)82. Male series location call with evenly spaced notes. (New Mexico, Wendy Kuntz, 4/5/96)83. Whistle contact calls of variable intensity by male and female. (New Mexico, Wendy Kuntz, 6/10/96)84. Agitated contact whistles by a pair. (New Mexico, Wendy Kuntz, 6/10/96)85. 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)86. Various cooing calls between pair. Cooing calls are variable soft calls often used when members of a pair are in close asso-ciation, such as when roosting together or allopreening. (New Mexico, Wendy Kuntz, 8/1/96)87. Variable contact-like calls and barks. (Arizona, Virginia Huber, ML 20870)88. Copulation sequence. (Arizona, Virginia Huber, ML 20869)

89. 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)90. Fledgling begging call. This call gradu-ally develops into the adult contact call. (New Mexico, Wendy Kuntz, 6/23/96)

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 inva-sion 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.91. Advertisement hooting. (Washington, J. R. Fletcher, ML 93740)

Spotted Owl x Barred Owl hybrid Strix occidentalis x varia

Barred Owl Strix varia

15

The Barred Owl is one of the most spectacu-lar 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 terri-tory frequently caterwaul, producing a vari-ety of spectacular hoots, squeals, and quacks. These caterwauling bouts are strictly per-formed by mated pairs, usually to announce or defend a territory against other Barred Owls. The ascending hoot is another territo-rial hooting variation commonly heard when one pair confronts another. Barred Owls are one of the few owl species that are com-monly heard throughout the day in many parts of their range, particularly in southern swamplands where breeding densities are the highest.92. Female two-phrase hoot, ascending hoot, and pair caterwauling. (South Carolina, Geoffrey A. Keller, ML 105433)93. Pair caterwauling. (Florida, William R. Evans, ML 49708)94. Pair caterwauling with nestling begging

call in background. (Arkansas, Gerrit Vyn and Benjamin M. Clock, ML 128923)95. Female two-phrase hoot, followed by male ascending hoot, and a female ascend-ing hoot variation. This variation is similar to that heard being given by an owl in flight on Track 100. (Arkansas, Gerrit Vyn and Benjamin M. Clock, ML 128930)96. 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)97. Territorial dispute between two pairs. Ascending hoots, caterwauling, and a boom-ing hoo-aw call are audible. (Arkansas, Gerrit Vyn and Benjamin Clock, ML 128926)98. Male hoo-aw call. This call may be used as a long distance contact call between mates. (Arkansas, Gerrit Vyn, ML 128927)99. Female hoo-aw call. Mates may use this call as a long distance contact call. (New York, Randolph S. Little, ML 106944)100. Female hoot variation. Females have been observed giving this call in flight while chasing other Barred Owls invading their ter-ritory. (Arkansas, Gerrit Vyn, ML 128931)

101. Female solicitation call from nest cavity. When incu-bating 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)102. 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)103. Fledgling begging call. (Florida, Robert C. Stein, ML 4549)104. Fledgling begging call and male two-phrase hoot. (Maryland, Wilbur L. Hershberger, ML 79462)

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Great Gray Owl Strix nebulosa

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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 dur-ing 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.105. 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 uncom-monly gives a higher-pitched, harsher version with fewer notes, prior to egg laying. Captive. (Alaska, Leonard J. Peyton, ML 49945) 106. 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)107. Defensive or warning hooting of an ag-gressive, highly agitated female. This call is of a greater intensity than the previous call and di-rected towards a threat to the nest. It is given by both sexes. (Oregon, David S. Herr, ML 48904)

108. Male contact hoots announcing a prey delivery to the nest. A female g-wuk call is also audible. (Minnesota, Lang Elliott, 6/14/93)109. Female contact call or whoop. The most common call given by the female, this vocal-ization 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)110. Female contact call or g-wuk. A varia-tion of the call on Track 109. 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)111. 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)112. Distraction calls. A female uttered these calls during a distraction or injury-feigning display near a nest. (Manitoba, Lang Elliott, 6/1/93)

113. Agitated call by a female after a distrac-tion display. (Manitoba, Lang Elliott, 6/1/93)114. 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 squir-rel (Tamiasciurus hudsonicus) is also audible. (Wyoming, Gregory F. Budney, ML 62945)115. Food exchange at nest site. First, a fe-male 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 chit-ter 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)116. Fledgling begging call. The howling of coyote (Canis latrans) is also audible. (Wyoming, Gregory F. Budney, ML 62947)

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Northern Hawk Owl Surnia ulula

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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. 117. 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)118. Trilling call. Both sexes use various trilling calls that are difficult to character-ize. They use these calls in many contexts, including during nest disturbances. The male and female also utter trilling calls in duet dur-ing prey exchanges and copulation. (Alaska, Leonard J. Peyton, ML 49902)

119. Screeching call or screeee-yip followed by yelping call. Both sexes commonly issue 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, in-cluding 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)120. Alarm squeals. An agitated owl near a nest uttered this call. It may be a distraction call. (Alaska, Leonard J. Peyton, ML 49910)121. Distress call. In winter, observers som-times hear low-intensity versions of this call, given by alarmed owls. Captive. (Ontario, William W. H. Gunn, ML 61801)

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Northern Pygmy-Owl Glaucidium gnoma

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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 “discom-fort call” may be more appropriate for de-scribing the “chitter” in other owl species.]122. 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)123. G.g. californicum. Male primary ad-vertising or toot song. This is the common single-note song of the subspecies G.g. cali-fornicum. Found throughout much of the interior West, this subspecies is also known

to give a double-note song (not heard here). (Montana, Robert C. Faucett, ML 25653)124. G.g. gnoma. Male primary advertis-ing 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)125. 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)126. Male primary advertising song inter-spersed 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 re-cording is unknown, although it seems to indicate a level of sexual excitement. It is probably analogous to the Ferruginous Pygmy-Owl sequence heard on Track 134. (Arizona, Frederick R. Gehlbach, 4/2/00)127. Female chitter call. (Arizona, Frederick R. Gehlbach, 4/2/00)128. Copulation calls. (Colorado, Robert Righter, 6/97)

129. 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 chit-ter calls. She receives the food and returns to the nest cavity. (Arizona, Frederick R. Gehlbach, 2000)130. Female chitter call fol-lowed by an unknown call. The voice of a researcher is briefly heard at the end of this recording. (Arizona, Bernard Lohr, 6/6/00)131. Fledgling begging call. (Washington, Charles A. Sutherland, ML 9419)

Jared Hobbs

Ferruginous Pygmy-Owl Glaucidium brasilianum

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A diurnal-crepuscular owl of extreme south-ern 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 oc-casionally at night. Its song varies widely in volume, frequency, and duration. Both males and females use a version of the primary ad-vertising 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). 132. Male primary advertising or territorial song. (Texas, Geoffrey A. Keller, ML 105563)133. Female primary advertising or territo-rial song. (Arizona, Greg Clark and Tim Price, 2/02)134. Male primary advertising song inter-spersed with prolonged chitter calls. The female utters soft chitter calls that seem to initiate the male’s use of the prolonged chit-ter. 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 Track 125. (Mexico, Andres M. Sada, FMNH 1019)

135. 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)136. Female alarm or pee-weeet call. Females often use this call when human intruders are near the nest. (Texas, Glenn A. Proudfoot, 6/99)137. Female aggression call. The owls ut-ter 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)138. Female aggression call. (Arizona, Greg Clark and Tim Price, 2/02)139. Nestling distress call. (Texas, Glenn A. Proudfoot)140. Fledgling begging chitter. The calls of Western Tanager (Piranga ludoviciana) are also prominent. (Texas, Glenn A. Proudfoot)

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Elf Owl Micrathene whitneyi

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North America’s smallest owl, this species is a common spring singer in parts of the Southwest. Although they are often associ-ated 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. 141. Male chatter song and female station call. The male uses the chatter song for terri-torial 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 selec-tion 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)142. Prolonged male chatter song and female calls. Males utter this song from within a potential nest cavity or its immedi-ate 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)143. Bark call and station call given by pair. The bark call is an alarm call or scolding call

directed at intruders, including humans, near the nest site. Used by both sexes, it varies in intensity depending on the owl’s level of agi-tation or alarm. A second bird can be heard giving the station call midway through the recording. (Arizona, Bernard Lohr, 6/6/00)144. Bark call. (Arizona, William W. H. Gunn, ML 59816)145. Copulation calls. (Arizona, J. David Ligon, ML 42361)146. Nestling begging rasp. (Arizona, Harriette Barker, ML 25169)

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Burrowing Owl Athene cunicularia

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Considered an accomplished vocalist, the Burrowing Owl is known to have a large rep-ertoire 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 vocal-izing birds. Burrowing Owls are most active vocally in the spring, though courtship and alarm calls can be heard throughout the year.147. 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)148. 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)149. Single alarm notes and alarm chatter. (Alberta, Albert Karvonen, ML 59807)150. Alarm chatter at burrow. (California, Gregory F. Budney, ML 126498)151. Nestling begging rasp and adult alarm chatter at burrow. (California, Gregory F. Budney, ML 126498)

152. 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)

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Boreal Owl Aegolius funereus

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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 primar-ily 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.153. 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) 154. 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 de-livered softly compared with the primary song. (Minnesota, Steven G. Wilson, 6/89)

155. 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)156. 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) 157. Food delivery or moo-a call. The male uses this variable call to announce food de-liveries 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) 158. Nestling peep and male food delivery call. (Minnesota, Steven G. Wilson, 6/89)159. Nestling chatter and female peep call from the nest. The female uses the peep call widely during the breeding season when solic-iting food from the male or as a contact call. This call is derived from the juvenile begging

call. (Alaska, Rosa Meehan, BLB 22369)160. 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)

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Northern Saw-whet Owl Aegolius acadicus

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The diminutive Northern Saw-whet Owl is most conspicuous during the brief period from February through April when most male sing-ing occurs. Throughout the rest of the year this species is heard infrequently or may be unrec-ognized by observers. The ksew call is a vari-able 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. 161. 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 soft-er, less-consistent version. (Oregon, Geoffrey A. Keller, ML 42199) 162. Advertising song. A young adult, pos-sibly a female, may have uttered this sporadic version. (New York, Thomas Knight, ML 89405)163. Whine-like call. (Utah, Kevin J. Colver, BLB 28001)164. 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 Track 163. Both ksew and whine calls are often 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)165. Calls recorded in winter. (Pennsylvania, Steve Farbotnik, 1/7/79 & 3/3/78) 166. Alarm call of male in response to an intruder near the nest. (Pennsylvania, Steve Farbotnik, 5/23/78) 167. Unknown call. Captive. (New York, Robert W. Dickerman, ML 8330)168. Bill snap and twittering chitter. Captive. (Ontario, William W. H. Gunn, ML 61810)169. Food deliveries at a nest. In the first sequence, nestling chitter calls and weak beg-ging calls are audible, followed by the male delivery call, a series of toots announcing a food delivery at the nest. In the second deliv-ery sequence, the difference between the beg-ging calls of two nestlings at different levels of development is apparent. (Pennsylvania, Steve Farbotnik, 6/21/78)

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Long-eared Owl Asio otus

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The diverse repertoire of the Long-eared Owl is primarily heard during the breed-ing 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 previ-ous 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.170. 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 approach-ing a nest. (Washington, David S. Herr, ML 49057)171. Female nest call. The female uses this variable call at the nest or its immediate vi-cinity. It may be a food solicitation call. It is heard in early spring during the period of

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) 172. Female nest call. This example has a sighing element. (New York, Lang Elliott, 3/22/92) 173. Pair duet with the female nest call in the foreground. The male’s advertising song is more distant. (Washington, David S. Herr, ML 48901)174. 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 wing-clap in nest defense. (Washington, David S. Herr, ML 47531) 175. 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)

176. Female barking alarm call at a nest. (New Jersey, George B. Reynard, ML 8350)177. Alarm call at a nest. (New Jersey, George B. Reynard, ML 8350)178. High intensity alarm call and bill-clap at a nest. (Manitoba, Lang Elliott, 6/13/93)179. Alarm call given in flight near a threatened nest. (George B. Reynard, ML 8350)180. Low intensity alarm call and bill-clap at a nest. These vocaliza-tions are often accompanied by the forward-threat posture. (New Jersey, George B. Reynard, ML 8350)181. Distraction squeal by a highly alarmed bird at a nest. (Manitoba, Lang Elliott, 6/13/93)182. Bill-clap and hiss by an alarmed bird at a nest. (New Jersey, George B. Reynard, ML 8350)183. Fledgling begging call. (Vermont, Matthew D. Medler, ML 126495)

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Short-eared Owl Asio flammeus

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The Short-eared Owl’s reputation as a quiet bird is undeserved. Even in winter, birds com-monly vocalize when interacting and foraging. The male’s courtship flight, wing-clapping, and hooting during courtship, are also con-trary 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 sev-eral unique vocalizations. Further research is needed to classify these calls and describe their behavioral contexts.184. 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)185. Bark call by an owl in flight. (Oregon, David S. Herr, ML 45302)

186. Bark calls by a flying owl in response to intruders near a nest. (Manitoba, Arthur A. Allen and Peter Paul Kellogg, ML 22671)187. Bark call by a perched owl near a com-munal winter roost. (New York, Gerrit Vyn, ML 128922)188. 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) 189. Female distraction call and bill-clap in response to a nest intruder. In cases of high intensity alarm at the nest, both sexes utter vari-ous squealing calls during an injury-feigning or distraction display. (Manitoba, Arthur A. Allen and Peter Paul Kellogg, ML 22672, 22674)190. Fledgling begging call. Captive. (Manitoba, Richard J. Clark, ML 22683)191. Fledgling chitter call. Captive. (Manitoba, Richard J. Clark, ML 22683)

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Extralimital Species

Mottled Owl Strix virgata

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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.192. Male advertising song or territo-rial hooting. (Chiapas, Mexico, Curtis A. Marantz, ML 127206)

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 occa-sions at Bentsen-Rio Grande Valley State Park in southern Texas. Like the similar Long-eared Owl, this species is known to produce a wing-clap in display flight.193. Male advertising song or hoot with fe-male call in response. This sequence may be analogous to the male advertising song and female nest call duet of Long-eared Owl (Track 173). Common Paraque (Nyctidromus albicol-lis) is vocalizing prominently in the back-ground. (Belize, George B. Reynard, 3/21/75)

Stygian Owl Asio stygiusAlphabetized Species List And Vocalization Types

Owl, Barn 2 Territorial scream 3 Territorial scream 3 Territorial scream, wing-clap 4 Warning scream 5 Distress call 7 Sustained defensive hiss, bill-clap, warning scream 8 Sustained defensive hiss 9 Kleak-kleak call 10 Calls at nest 11 Fledgling mobbing call 12 Fledgling begging snoreOwl, Barred 92 Female two-phrase hoot, ascending hoot, caterwaul 93 Pair caterwauling 94 Pair caterwauling 95 Female two-phrase hoot, male ascending hoot, female hoot variation 96 Ascending hoot, two-phrase hoot, caterwaul 97 Ascending hoot, caterwaul, hoo-aw 98 Male hoo-aw 99 Female hoo-aw 100 Female hoot variation 101 Female solicitation call 102 Distraction squeals and honk 103 Fledgling begging call

104 Fledgling begging call, male two-phrase hootOwl, Barred x Spotted 91 Advertisement hootingOwl, Boreal 153 Male staccato song 154 Male prolonged staccato song 155 Male subdued staccato song 156 Skiew call 157 Male food delivery call 158 Nestling peep, male food delivery call 159 Nestling chatter, female peep 160 Fledgling begging call, male food delivery call, skiew callOwl, Burrowing 147 Male primary song 148 Alarm chatter 149 Alarm notes, alarm chatter 150 Alarm chatter 151 Nestling begging rasp, adult alarm chatter 152 Juvenile rattlesnake raspOwl, Elf 141 Male chatter song, female station call 142 Prolonged male chatter song, female call 143 Bark call, station call 144 Bark call 145 Copulation 146 Nestling begging rasp

Species are listed alphabetically. Vocalizations are preceded by track number. They are listed in the order in which they appear on the guide.

Owl, Flammulated 13 Male territorial hoot 14 Female hoot 15 Nestling begging snore, adult food delivery hoot 16 Female bark, nestling begging snore 17 Male bark 18 Female moan 19 Distress shriek, bill-clapOwl, Great Gray 105 Male territorial hoot 106 Defensive hoot 107 Defensive hoot 108 Male contact hoot 109 Female contact call 110 Female contact call, nestling begging call 111 Chitter call 112 Distraction calls 113 Agitated call 114 Fledgling begging call, hoot 115 Food exchange at nest 116 Fledgling begging callOwl, Great Horned 45 Territorial hooting duet 46 Territorial hooting duet, copulation 47 Female squawk, male territorial hoot 48 Female chitter call, squawk, male territorial hoot 49 Male territorial hoot, female territorial hoot, squawk 50 Bark-like call

51 Female wac-wac call, bill-clap, male hoot 52 Chitter call 53 Fledgling begging callOwl, Long-eared 170 Male advertising hoot 171 Female nest call 172 Female nest call 173 Female nest call, male advertising hoot 174 Male wing-clap, female nest call 175 Male bark 176 Female bark 177 Alarm call 178 High intensity alarm call, bill-clap 179 Alarm call in flight 180 Low intensity alarm call, bill-clap 181 Distraction squeal 182 Bill-clap, hiss 183 Fledgling begging callOwl, Mottled 192 Male territorial hootOwl, Northern Hawk 117 Male advertising song 118 Trilling call 119 Screeching call, yelping call 120 Alarm squeals 121 Distress callOwl, Northern Saw-whet 161 Male advertising song 162 Advertising song 163 Whine-like call

164 Ksew call, whine call, whine-like call 165 Calls 166 Male alarm call 167 Unknown call 168 Bill snap, chitter call 169 Food deliveries at nestOwl, Short-eared 184 Male hoot, wing-clap 185 Bark call 186 Bark call 187 Bark call 188 Bark call 189 Female distraction call, bill-clap 190 Fledgling begging call 191 Fledgling chitter callOwl, Snowy 54 Male territorial hoot 55 Female bark call, bill snap 56 Male bark call 57 Female mewing whistle 58 Unidentified call 59 Unidentified call 60 Nestling begging squeal, chitter call 61 Fledgling begging call, chitterOwl, Spotted (“Mexican”) 76 Male four-note location call 77 Male four-note location call 78 Female four-note location call 79 Female agitated location call, male four-note location call, female agitated contact whistle 80 Agitated location call

81 Male series location call 82 Male series location call 83 Whistle contact call 84 Agitated contact whistle 85 Bark series 86 Cooing call 87 Contact-like call, bark 88 Copulation 89 Prey delivery 90 Fledgling begging callOwl, Spotted (“Northern”) 62 Male four-note location call 63 Female four-note location call 64 Female three-note location call 65 Male five-note location call 66 Male series location call, female contact whistle 67 Female series location call 68 Female series location call, agitated contact whistle 69 Male series location call, female contact whistle 70 Contact whistle 71 Female agitated contact whistle 72 Female bark series 73 Female contact whistle, male nest call 74 Pair interaction 75 Pair interactionOwl, Stygian 193 Male advertising hoot, female callPygmy-Owl, Ferruginous 132 Male primary advertising song

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133 Female primary advertising song 134 Male primary advertising song, prolonged chitter call, female chitter call 135 Female chitter call 136 Female alarm call 137 Female aggression call 138 Female aggression call 139 Nestling distress call 140 Fledgling begging chitterPygmy-Owl, Northern 122 Male toot song (G.g. grinnelli) 123 Male toot song (G.g. californicum) 124 Male toot song (G.g. gnoma) 125 Male double-note toot song (G.g. gnoma) 126 Male toot song, prolonged chitter call, female chitter call 127 Female chitter call 128 Copulation 129 Food delivery at nest 130 Female chitter call, unknown call 131 Fledgling begging callScreech-Owl, Eastern 25 Descending trill, monotonic trill 26 Descending trill 27 Monotonic trill 28 Monotonic trill 29 Monotonic trill 30 Screech call, bill-clap 31 Screech call, chuckle rattle 32 Bark call

33 Nestling begging rasp, chitter call, chuckle rattle 34 Food delivery at nestScreech-Owl, Western 20 Bouncing ball song, double trill song 21 Double trill song, bouncing ball song 22 Agitated bark, bill-clap 23 Te-te-do call, agitated double trill 24 Female solicitation callScreech-Owl, Whiskered 35 Male short trill 36 Male short trill 37 Male telegraphic trill 38 Telegraphic trill, squeal 39 Male prolonged trill 40 Hoot 41 Male whistle call 42 Bark series 43 Female bark call, screech 44 Copulation

PROduceR / StudIO engIneeR / SOund SelectOR / text AuthORGerrit Vyn

cO-PROduceRGregory F. Budney

PROductIOn MAnAgeRMary S. Guthrie

SuPeRvISIng engIneeRRobert W. Grotke

dIgItAl IMAgeSDiane McAllister, Herbert Clarke, Herbert G. Fischer, Diana LeVasseur, Jim Milmoe, Cameron Rognan, Nick Saunders, Dominic Sherony, Ted Shroeder, Peter R. Stettenheim, Jim Weaver and US Fish and Wildlife.

Front and back cover photographs courtesy of Gerrit Vyn www.gerritvynphoto.com

© 2006 Cornell Lab of Ornithology

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