Justification This species is classified as Vulnerable because it has a very small range. It is restricted to two mountain ranges on one island, and, although it has apparently adapted to non-native habitats, it remains at risk from the effects of exotic taxa, especially the possible introduction of disease-carrying mosquitoes capable of tolerating the cooler climate at high altitudes.

Family/Sub-family Fringillidae

Species name author (Bloxham, 1827)

Taxonomic source(s) AOU checklist (1998 + supplements)

Identification 11 cm. Small honeycreeper with short, downcurved bill. Male all golden-yellow below, sharply contrasting with olive-green upperparts. Black lores, with yellow supraloral spot. Female greenish-grey above, pale yellowish-white below, with prominent wing-bars of same colour. Dark grey lores, yellowish-white supraloral spot. Juvenile male duller than adult, with two buffy wing-bars. Similar spp. Male O`ahu `Alauahio Paroreomyza maculata has straight bill, bold yellow stripe over eye and dark stripe through eye. Female has dark line behind eye only and pale lores. Introduced Japanese White-eye Zosterops japonicus has straight bill, bold white eye-ring. Voice Song a vigorous trill of single notes. Call a short cat-like buzzy note. Hints Easily seen at fairly low elevation around flowering trees in mountains behind Honolulu.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

20,000 - 60,000

stable

380 km²

Yes

Range & population Hemignathus flavus is endemic to O`ahu in the Hawaiian Islands (USA). It originally occurred throughout the island, but is now restricted to the two mountain ranges. In the Wai`anae Mountains, it is uncommon and sparsely distributed, mostly above 500 m elevation. In the southern and central Ko`olau Mountains, it is locally common, occurring from the summits occasionally down to 30 m in valleys, but it becomes increasingly rare northwards and is practically absent from the northern tip of the range<sup>2</sup>. The population is estimated at 20,000-60,000 birds<sup>1,2</sup>, but surveys on O`ahu, unlike those on other Hawaiian islands, have not been systematic and these estimates may be too high³. Christmas bird counts indicate a population decline over the period 1958-1985², but more recent information indicates that the population may be stable and even increasing in some areas^1,2.

Ecology: It has adapted relatively well to forests of non-native trees, but is most abundant in native forests, particularly where koa trees dominate². It nests and forages in urban areas where enough trees grow². Little is known about its diet, but it probably feeds primarily on small insects and other arthropods, taking nectar and fruit as secondary food sources².

Threats Feral ungulates and introduced predators are likely to have contributed to historical declines² and to be continuing limiting factors. Diseases spread by introduced mosquitoes were probably also a major factor, but some populations have apparently developed some degree of resistance to avian malaria, and this may explain recent population increases in lowland areas².

Conservation measures underway No specific conservation measures are known for this species.

Conservation measures proposed Monitor the population. Perform further research², especially on the reasons for its relative scarcity in the Wai`anae Mountains. Protect native habitats by law. Reforest cleared areas.

References 1. Jacobi and Atkinson (1995). 2. Lindsey et al. (1998). 3. R. Shallenberger in litt. (1999).

Text account compilers Phil Benstead (BirdLife International), Alison Stattersfield (BirdLife International), Tom Stuart (BirdLife International), Joe Taylor (BirdLife International)

Contributors Rick Camp (US Geological Survey), Scott Fretz (Hawaii Division of Forestry and Wildlife), Marcos Gorresen (US Geological Survey), Rob Shallenberger (The Nature Conservancy), Eric VanderWerf (US Fish & Wildlife Service), Bethany Woodworth (US Geological Survey)

IUCN Red List evaluators Stuart Butchart (BirdLife International), Joe Taylor (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Hemignathus flavus. Downloaded from http://www.birdlife.org on 9/2/2010

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.

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