Kauai Oo Moho braccatus Scientific name definitions

Paul W. Sykes Jr., Angela K. Kepler, Cameron B. Kepler, and J. Michael Scott
Version: 1.0 — Published March 4, 2020
Text last updated January 1, 2000

Sounds and Vocal Behavior



No information.

Vocal Array

Kaua‘i ‘Ö‘ö. Vocalizations published by H. D. Pratt (Pratt 1996) from recordings by Thane K. Pratt (LNS 56465), Robert J. Shallenberger (LNS 06031), and C. Fred Zeillemaker (LNS 62430) archived at Library of Natural Sounds (LNS), Laboratory of Ornithology, Cornell University (A. L. Priori pers. comm.). Recordings by John L. Sincock have not been located and may be lost. Vocalizations characterized as melodious, loud, clear, flutelike, liquid-sounding, bell-like, and resembling those of other ‘ö‘ö, but much more complex (Wilson and Evans 1890, Perkins 1903, Conant et al. 1998, J. L. Sincock unpubl., PWS). Calls variable, typically low, mellow whistles (Richardson and Bowles 1964). This species responded readily to imitations of its calls (Richardson and Bowles 1964, J. L. Sincock unpubl.). Considered among finest singers of native Hawaiian birds (Munro 1944a). See Figure 3 for examples of long complex song series.

At least 2 complex song series (Pratt 1996), consisting of loud melodious whistles reminiscent of Western Meadowlark (Sturnella neglecta); tone distinctly meliphagine, with haunting echo quality (Conant et al. 1998). Song includes 2-note phrases that probably resemble the oh-oh from which bird's name is derived (Conant et al. 1998). Pairs frequently duet, but female has fewer notes (Munro 1944a). Call notes include distinct took-took, like that of Hawai‘i ‘Ö‘ö (see below), but sharper and higher-pitched (Munro 1944a); the call most often heard, a loud whistled whip-poor-weeo, which is not too fast and descends at the end (Richardson and Bowles 1964); loud ah-ö or ö-ö (Richardson and Bowles 1964, J. L. Sincock unpubl.); distinct repetitive squeak by female when alarmed (Perkins 1903); screamlike distress call that is similar to that of a wounded Tui (Prosthemadera novaeseelandiae), a meliphagid of New Zealand (Munro 1944a); double-note keet-keet alarm call (Hawaii Audubon Society 1989); and sharp, 2-note whistle, which can be heard in second song type presented in Pratt (Pratt 1996) tape and appears to have been an alarm or alert call note (Conant et al. 1998). These latter 2 calls may be the same as J. L. Sincock's (unpubl.) short, loud, mellow “ beep-beep ” or “ paw-paw ” whistles, given at 1- to 3-min intervals by both members of pair.

O‘ahu ‘Ö‘ö. Vocalizations not described from the wild. Presumably from captive birds, Andrew Bloxam described note as a harsh chirp of 2–3 different tones (Olson 1996b). Nothing else known of repertoire.

Bishop's ‘Ö‘ö. Henry Palmer (in Rothschild 1893a –226) described vocalizations of Bishop's ‘Ö‘ö as follows: “It has a call-note not unlike that of the Hawaiian O-o (M. nobilis), but neither so loud or muffled in tone, somewhat like ‘ O-ó,' the accent being on both syllables. This call-note is not so full and loud if uttered by the female. Quite a variety of other notes were observed: a kind of a chuckling note, heard but once, and a high clear flute-like whistle as if the bird was trying to sing. Another note is somewhat like a cat's cry, I should say like ‘ wháo .' Another time again sounds were frequently repeated which sounded to me like ‘ Ponk,' finishing with the cat-like ‘ wháo .'”

Perkins's (Perkins 1903: 443) rendering of vocalizations is as follows: “The cry of the Oo is unlike that of any other native bird, and no one who has once heard and identified it can ever again be in doubt as to the bird that utters it. This cry is usually dissyllabic [sic], as represented by the bird's name, but sometimes may be represented by only a single sound. It varies somewhat, especially in loudness and clearness, according to the season, and is either uttered once or repeated. Thus at certain seasons the usual cry of the Moloka‘i bird at its fullest was well represented by five syllables, ‘owów, owów, -ów,' the first and the second, as likewise the third and fourth, are practically continuous, with the stress on the latter in each case; there is a slight pause between the first and second pair of syllables and generally a longer and distinct one between the latter of these and the final one, which is extremely loud and might at times be almost termed a shriek.”

Hawai‘i ‘Ö‘ö. Peale (Peale 1848) said that in voice and manner this species bears some resemblance to Baltimore Oriole (Icterus galbula). Wilson (Wilson 1890a: 180) described call as “somewhat harsh and resembles the sound of the letter O, repeated twice; with a well-marked pause between.” Perkins (Perkins 1893b) described call as more like “ ow-ow ” than “ oo ”; Munro (Munro 1944a) described call as deep “ took took,” while Henshaw (Henshaw 1902a) interpreted call as “ chook chook .” Another note was a loud chuck, repeated 2–3 times (Wilson and Evans 1890). Henshaw (Henshaw 1902a) stated that neither these syllables nor any others truly capture sounds made by this species or represent its peculiar rhythm with its ventriloquial quality. Calls are audible at great distance; may be heard up to about 800 m away (Perkins 1903). Hawai‘i ‘Ö‘ö readily responded to imitations of its calls (Perkins 1893b, Henshaw 1902a). Song repertoire of this species not described. Song said to be distinctive, but not loud like calls, singing taking place infrequently (Perkins 1903). From Palmer's notes, Rothschild (Rothschild 1893a) described song as short, with little melody, consisting of a squeaking noise and a few other notes, which are seldom heard. According to Munro (Munro 1944a), both sexes have brief song, not as loud, vigorous, or pleasing to the ear as song of Kaua‘i ‘Ö‘ö.

Kioea. Peale (Peale 1848: 148) stated, “disposed to be musical”; song presumed to be loud; Wilson and Evans (Wilson and Evans 1890) quoting from Cassin (Cassin 1858b), stated, “Dr. Pickering [with Peale on U.S. Exploring Expedition] mentions having seen this species ‘alight in the tops of the trees and uttering a loud CHUCK .'” Nothing further known of vocalizations.


Kaua‘i ‘Ö‘ö. Gave calls throughout year (Hancock 1966, J. L. Sincock unpubl.), but less frequently when not breeding; generally sang only during breeding activities (J. L. Sincock unpubl.).

Bishop's ‘Ö‘ö. Probably sang throughout year, but most intensely during breeding. See discussion of vocal array, above. Call sometimes audible at 1,000 m. Responded to imitations of its calls (Perkins 1903).

Hawai‘i ‘Ö‘ö. Gave calls throughout year; probably sang only during breeding season. According to Perkins (Perkins 1903), called incessantly when gathered in large numbers to feed at flowering patches and during brief flights between patches.

Daily Pattern

Kaua‘i ‘Ö‘ö. Sang primarily in early morning and early evening (Perkins 1903). Wilson and Evans (Wilson and Evans 1890) referred to singing in early morning. Rothschild (Rothschild 1893a: [Di.] 20), quoting from Henry Palmer's diary, Kaua‘i I., 16 Jun 1893, stated, “Everywhere here the trees appear to be alive with birds. The noise of their various songs was quite deafening this afternoon. The ‘boom' of the ‘o‘o (Moho braccata) and the powerful song of the ‘Kamao' (Phaeornis myiadestina, Stejn.) were noticeable above the others.” It is not clear whether this passage refers to songs or calls, or to both. J. L. Sincock (unpubl.) reported that vocalizations during breeding season started about 06:00 and ceased around 19:00; less frequent from 11:00 to 15:00. More active vocalizing during infrequent brief periods of 5–10 min of sunshine than long periods of cloud cover and rain. A pair observed 2–5 Oct 1974 vocalized daily between 06:00 and 07:30 and again at about 18:30, whereas on 25–26 Mar, at onset of breeding, vocalized about every 20 min from 06:00 to 07:30, then every 40 min until 10:30. In early Jul 1975, Conant et al. (Conant et al. 1998) reported singing at 10- to 20-min intervals until about 10:30, after which song activity was less frequent. Duetting was frequent throughout day (Conant et al. 1998).

Hawai‘i ‘Ö‘ö. In good weather, mostly silent during heat of day, but during wet or foggy weather, vocal throughout day (Perkins 1903).

Places Of Vocalizing

Kaua‘i ‘Ö‘ö. Probably called from perches anywhere within forest strata and sang at nest site and elsewhere in breeding territory. Mated pairs frequently perched in uppermost dead bare branches of ‘öhi‘a, sitting side by side vocalizing (J. L. Sincock unpubl.).

Hawai‘i ‘Ö‘ö. Apparently gave calls throughout forest strata and sometimes in flight, but gave song from denser part of forest strata (Perkins 1903).

Repertoire And Delivery Of Songs

No information.

Social Context And Presumed Functions

Kaua‘i ‘Ö‘ö. Little known. See discussion of vocal array, above.

Hawai‘i ‘Ö‘ö. Little known. At top of dominance hierarchy of nectarivores on Hawai‘i I.; used its call notes and other behaviors in threat displays to defend flower patches rich in nectar against other species, ‘I‘iwi in particular (Perkins 1903). During nonbreeding period, while foraging in pairs or small flocks, gave call notes incessantly (Henshaw 1902a, Perkins 1903), apparently communicating among family members and/or conspecifics.

Nonvocal Sounds

Kaua‘i ‘Ö‘ö. Wings make noisy flapping sound in flight (Hart 1976, J. L. Sincock unpubl.).

Hawai‘i ‘Ö‘ö. Wings make continuous buzzing sound in flight (Munro 1944a).

Kauai Oo Figure 3. Vocalizations of Kauai Oo
Figure 3. Vocalizations of Kauai Oo

Selected examples of long complex Kaua‘i ‘Ö‘ö song series recorded by Thane K. Pratt 15 Aug 1976, in Alaka‘i Swamp, Kaua‘i I. At least 9 song types were sung in a rough order, AI. There appears to be a B song type sung without terminal low note, usually followed by another song type in close proximity, labeled B’. Examples of song types in sequence are as follows: (A) A B C D, (B) B’ B’ B’ E, (C) B’ B’ C DB, (D) D DB, (E) B B C D DB B’ B’ E, and (F) B’ B C F G H I. Entire song, three-fourths of which is in first song series in Pratt 1996, is as follows: A B C D B C D B’ B’ B’E B’B’B C DB B B C D DB B’B’E C D B B’B C F G H I. Interpretation of song types by Gerald E. Hough II. Sonograms prepared by Borror Laboratory of Bioacoustics, Ohio State University, using Kay Elemetrics DSP Sona-Graph 5500 (with 150-Hz effective frequency resolution and 200-point FFT transform size) from recordings of Library of Natural Sounds, Laboratory of Ornithology, Cornell University (LNS no. 56465).

Recommended Citation

Sykes Jr., P. W., A. K. Kepler, C. B. Kepler, and J. M. Scott (2020). Kauai Oo (Moho braccatus), version 1.0. In Birds of the World (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.kauoo.01