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Iiwi Vestiaria coccinea
BirdLife is updating this factsheet for the 2016 Red List
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This species is listed as Vulnerable because it has a small and contracting range and, although it is still relatively abundant, surveys have shown that it is undergoing a continuing population decline.

Taxonomic source(s)
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Distribution and population
Vestiaria coccinea formerly occurred on all the main islands in the Hawaiian Archipelago (USA) but it is now extinct on Lana'i and relict populations (probably fewer than 50 individuals [J. Lepson in litt. 2000]) remain on O`ahu and Moloka`i (Scott et al. 1986, P. Donaldson in litt. 1999). Recent population estimates are: c.385,000 individuals, excluding birds on O`ahu, during 1976-1983 (Scott et al. 1986) and more than 350,000 individuals in the early 1990s following recent declines in several populations (Jacobi and Atikinson 1995). There is now evidence from monitoring (much of it unpublished) that the species has declined throughout the Hawaiian islands, except on windward Mau`i and at Hakalau, Hawai`i, where the populations appear to be stable (D. Pratt in litt. 2007). The numbers of individuals detected during monitoring have fallen at both mid and low elevations (D. Pratt in litt. 2007). The apparent decline appears to have been most pronounced in western Hawai`i, although there is little quantitative data for this area (D. Pratt in litt. 2007).

Population justification
An estimate of more than 350,000 individuals was made in the early 1990s (Jacobi and Atikinson 1995).

Trend justification
The population is declining (figures still to be published), owing to avian malaria and other factors.

This species was formerly found in forests at any elevation, and still occurs in a variety of native, disturbed and unnatural habitats from 300 to 2,900 m (Berger 1972, Scott et al. 1986). The greatest densities are found at 1,300-1,900 m, and low elevation populations may be sustained primarily by dispersal from mid-elevation populations (Scott et al. 1986).

The exact causes for the decline are uncertain, although it is known that the species is very susceptible to avian malaria, carried at low elevations by introduced mosquitos (Jacobi and Atikinson 1995, D. Pratt in litt. 2007). Other factors which are likely to be contributing to its decline include habitat degradation and predation by introduced mammals such as cattle, pigs, cats and rats.

Conservation Actions Underway
The species is the subject of population trend analysis and detailed studies into the effects of avian malaria by the U.S. Geological Survey Pacific Island Ecosystems Research Centre. Conservation Actions Proposed
Complete assessment of current population trends. Study the factors driving the decline. Attempt to mitigate against the decline.

Berger, A. J. 1972. Hawaiian birdlife. University Press of Hawaii, Honolulu.

Jacobi, J. D.; Atkinson, C. T. 1995. Hawaii's endemic birds. In: LaRoe, E.T. (ed.), Our living resources: a report to the nation on the distribution, abundance, and health of US plants, animals, and ecosystems, pp. 376-381. U.S. Department of the Interior, National Biological Service, Washington, D.C.

LaPointe, D. A. 2006. Feral pigs, introduced mosquitoes, and the decline of Hawai'I's native birds.

Scott, J. M.; Mountainspring, S.; Ramsey, F. L.; Kepler, C. B. 1986. Forest bird communties of the Hawaiian Islands: their dynamics, ecology, and conservation. Cooper Ornithological Society, California.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Derhé, M., O'Brien, A., Stuart, T., Taylor, J.

Camp, R., Donaldson, P., Fretz, J., Lepson, J., Pratt, H., Roberts, P., VanderWerf, E., Hart, P.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2016) Species factsheet: Vestiaria coccinea. Downloaded from on 23/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 23/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Iiwi (Vestiaria coccinea) 0

Key facts
Current IUCN Red List category Vulnerable
Family Fringillidae (Finches and Hawaiian honeycreepers)
Species name author (Forster, 1780)
Population size mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 19,800 km2
Country endemic? Yes
Links to further information
- Additional Information on this species