Justification This species qualifies as Vulnerable because it has a very small range. It survives in a very small occupied area of upland forest on one island, where it is at risk from the effects of exotic taxa. It is close to qualifying as Endangered, but appears able to tolerate some disturbance to its habitat.

Family/Sub-family Fringillidae

Species name author (Stejneger, 1887)

Taxonomic source(s) AOU checklist (1998 + supplements), Sibley and Monroe (1990, 1993)

Synonyms Viridonia parva Sibley and Monroe (1990, 1993), Viridonia parva Collar et al. (1994)

Identification 10 cm. Small honeycreeper with short, thin, slightly curved bill. Male bright yellow with no dark feathering in lores. Dark wing and tail feathers broadly edged yellow. Female and juvenile similar but less bright. Similar spp. Kaua`i `Amakihi H. kauaiensis, `Akeke`e Loxops caeruleirostris, and Kaua`i Nukupu`u H. lucidus hanapepe all have dark lores and different bill shapes. Introduced Japanese White-eye Zosterops japonicus has straight bill and bold white eye-ring. Voice Song a vigorous trill of doubled or tripled notes weesee-weesee-weesee- or weesity-weesity-weesity- etc. Typical call a 2-note tew-weet, down then up. Also a loud, single chirp similar to call of H. kauaiensis. Hints Easily seen at Koke`e.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

44,000

increasing

320 km²

Yes

Range & population Hemignathus parvus is endemic to Kaua`i in the Hawaiian Islands (USA), where it occurred almost throughout the island in the 19th century but, by 1900, had become uncommon to rare in lowland forests<sup>2</sup>. In 1968-1973, surveys estimated 24,230 birds, largely restricted to upper elevations<sup>8</sup>. Surveys of the Alaka`i and Kôke`e areas in 2000 yielded an estimate of c.34,500 individuals in these areas<sup>9</sup>. In 2003, the total population was put at 44,359 individuals<sup>10</sup>. In 1992, Hurricane Iniki devastated forests throughout Kaua`i and all bird populations on the island appeared to have been drastically reduced^4,5. However, it would seem that this species has recovered and appears to be increasing^5,9.

Ecology: It inhabits `ohi`a and native mixed forest mainly above 600 m, but has been found as low as 100 m (especially in the north-west of the island)^2,6,8, although it is not known whether this is still the case³. It is able to tolerate considerable habitat disturbance, but at lower population densities². It feeds on nectar and arthropods (especially caterpillars and spiders) and nests in `ohi`a trees².

Threats From the late 1890s, significant declines have been associated with habitat loss and degradation (either owing to clearance for timber and agriculture, or to introduced herbivores), and the spread of avian diseases². Ongoing development in the Kôke`e area continues to diminish the amount of habitat available, and the spread of exotic plants into native habitats, although tolerated, is associated with lower densities<sup>2</sup>. Introduced mosquitoes, which spread avian pox and malaria, are now common at 900 m, and may be breeding as high as 1,200 m elevation<sup>2</sup>. Under a 2<sup>o</sup>C warming scenario and an increase in rainfall over high-elevation forests during the next 100 years, in keeping with climate model predictions for the region, the prevalence of malaria on Kaua`i is predicted to increase within the remaining habitat¹¹. The 17 ^oC isotherm, below which Plasmodium prevalence peaks, is predicted to shift upwards by around 300 m, decreasing the area of forest where Plasmodium prevalence is limited by 85%¹¹. Feral pigs facilitate the spread of both alien plants and mosquitoes and, with other ungulates, continue to degrade native forests⁵. Predation by introduced animals (rats and possibly cats and Barn Owls Tyto alba) is an additional pressure², while other introduced taxa (especially the Japanese White-eye Zosterops japonicus, wasps and ants) compete for arthropod resources². Invasive plants have degraded significant portions of Kôke`e State Park and threaten the remainder of the habitat<sup>12</sup>. This species's restriction to Kaua`i and dependence on canopy species makes it vulnerable to catastrophic events such as hurricanes¹².

Conservation measures underway Its habitat is protected in the Alaka`i Wilderness Preserve and to some extent in the Kôke`e State Park. An upper portion of the Alaka`a Wilderness Preserve is due to be fenced and ungulates will be removed from inside the fenced area, however other areas of the preserve and state park apparently lack active management¹³.

Conservation measures proposed Monitor population trends through regular surveys. Control and prevent further introductions of non-native animals and plants, particularly in the Alaka`i Wilderness Preserve^2,7. Restore habitats². Identify and encourage disease-resistant lineages, e.g. by translocation, captive propagation², provision of supplementary resources, nest protection and introduced predator/competitor control.

References 1. Jacobi and Atkinson (1995). 2. Lepson (1997). 3. J. Lepson in litt. (1999). 4. Pratt (1993). 5. Pratt (1994). 6. Pratt et al. (1987). 7. Scott et al. (1986). 8. USFWS (1983). 9. Foster et al. (2004). 10. USFWS in litt. (2003). 11. Benning et al. (2002). 12. P. Roberts in litt. (2007). 13. R. Camp in litt. (2007).

Further web sources of information

Audubon WatchList

Text account compilers Phil Benstead (BirdLife International), Isabel Isherwood (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), Jaan Lepson, H. Douglas Pratt (North Carolina State Museum of Natural Sciences), Pauline Roberts (Hawaii Division of Forestry and Wildlife), 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 parvus. Downloaded from http://www.birdlife.org on 10/2/2010

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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