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

Demography and Populations

Measures of Breeding Activity

Age At First Breeding



Kaua'i 'Ö'ö. No information, but 1 nest contained 2 young (J. L. Sincock unpubl.), so clutch size in this case was at least 2 eggs, possibly more.

Annual And Lifetime Reproductive Success


Number Of Broods Normally Reared Per Season

Possibly more than 1.

Life Span and Survivorship

Kaua'i 'Ö'ö. No information; however, the last surviving individual, believed to be a male, was at least 4 yr old.

Disease and Body Parasites


In 1826, Mexican night-biting mosquito (Culex quinquefasciatus) was introduced to Maui and quickly spread to other islands (Warner 1968a). Beginning in 1865, alien birds from all over the world were introduced to the islands (Scott et al. 1986). Since then a long list of avian pathogens and parasites has been catalogued in Hawai'i (van Riper and van Riper 1985). Chief among them in terms of virulence to native avifauna (Warner 1968a, van Riper and van Riper 1985, Van Riper et al. 1986, Atkinson et al. 1995), which had evolved in absence of significant diseases, are avian malaria (Plasmodium relictum) and avian pox (Poxvirus avium). Both diseases are spread by C. quinquefasciatus, although pox can also spread by contact. Perkins (Perkins 1893b) first noted poxlike lesions on Hawaiian birds in early 1890s. Since then, pox has been described in >20 species of birds in Hawai'i (Scott et al. 1986). Avian malaria is particularly virulent to Hawaiian birds. By the time malaria arrived, C. qinquefasciatus had invaded all islands up to 1,650 m elevation (Goff and Van Riper III 1980, Van Riper et al. 1986), although in decreasing density at higher elevations. Unfortunately, birds at higher (safe) elevations fly down-slope during inclement weather or periods of local food abundance, at which time exposure to malaria is increased.

Kaua'i 'Ö'ö. Female collected on 23 May 1891 by Henry C. Palmer (ROM 59936) had poxlike lesions on 1 toe (Glenn Murphy pers. comm.). Avian malaria and pox, separately and in combination, probably were partly responsible for extinction of Kaua'i 'Ö'ö.

Hawai'i 'Ö'ö. Avian malaria and pox may have been partly responsible for disappearance of this species.

Body Parasites

No information.

Causes of Mortality

No information.

Population Spatial Metrics

Kaua'i 'Ö'ö. Fidelity to nesting territory strong during breeding and from year to year.

Population Status

Kaua'i 'Ö'ö. In twentieth century, known only from Alaka'i Swamp of central Kaua'i I. No estimates exist for population before 1960s. For 1968-1973, Sincock et al. (Sincock et al. 1984) estimated population at 36 birds ± 22 SE (95% confidence interval [CI]), and by 1981 (Scott et al. 1986), estimated population had decreased to 2 birds ± 2 SE (95% CI; estimated effective detection distance of 150 m). Now probably extinct; last seen in 1985 (Pyle 1985a), and last heard calling, but not seen, in 1987 (Pyle 1987). No reliable reports since.

O'ahu 'Ö'ö. Population was large (probably in thousands) sometime before Western contact (1778), since substantial numbers of O'ahu 'Ö'ö were taken for Hawaiian feather work (Kaeppler 1970). Although large numbers were taken, few were obtained for science. Last reports were in 1837 (Rothschild 1907, Greenway 1958) or, if correct, 7 Sep 1840 (AMNH 306357), all collected by Ferdinand Deppe, probably in Nu'uanu Valley, O'ahu I.

Bishop's 'Ö'ö. No information on numbers, but still widespread in late 1800s.

Hawai'i 'Ö'ö. No estimates of population exist; given the number required to make feather artifacts by Hawaiians (Brigham 1899, Kaeppler 1970, Rose et al. 1993), however, and on the basis of writings of early naturalists and ornithologists (Peale 1848, Wilson 1890a, Henshaw 1902a, Perkins 1903), population probably totaled many thousands.

Kioea. No information on numbers; considered rare when discovered in 1840 (Peale 1848) and extinct shortly after 1859 (Munro 1944a).

Population Regulation

Kaua'i 'Ö'ö. Since end of nineteenth century, habitat loss and modification, avian disease, and introduction of rodents have all severely affected populations, resulting in extinction in <90 yr.

O'ahu 'Ö'ö. No information; habitat loss and modification, and overexploitation, likely were the causes of extinction.

Hawai'i 'Ö'ö. Habitat loss and modification, avian diseases, introduced rodents, and heavy hunting pressure for feathers and meat devastated populations.

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