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Status: Population size: 40,000

Oahu Amakihi
(Hemignathus flavus)

One of a group of small, closely related, island specific Hawaiian honeycreepers. The Oahu 'Amakihi was formerly considered a subspecies of the Common 'Amakihi but is endemic only to the island of Oahu and is now granted full species status.

Identification
Small, olive green birds with black lores and short, curved bills. Could be confused with the extremely rare Oahu 'Alauahio (Paroreomyza maculata) which has a straighter bill and a yellow (in males) or white (in females) forehead. In behavior, the Amakihi both creeps along trunks and branches, and spends time drinking nectar from flowers by plunging its face into the interior of blossoms. Call is a sweet, while song is a short trill.

Distribution and Population Trends
Found only on the island of Oahu, where it once occurred throught the island but is now found only in the Ko'olau and Wai'anae Mountains. Within those areas it utilizes a wide variety of forests with both native and introduced species. Able to maintain populations at lower elevations than other native Hawaiian passerines, even being found in suburban yards and parks and in highly disturbed areas with large populations of introduced birds. It is thought that this species is expanding into low elevations and repopulating portions of its former range, perhaps by developing resistance to avian malaria and pox. Preliminary analyses of Audubon Christmas Bird Count data show a decline in abundance of the species since the early 1980's.

Ecology
Little studied and poorly known despite living on one of the most populous of the Hawaiian Islands and being widespread and locally common. This species has a generalized and adaptable foraging strategy, finding its food among flowers, leaves, twigs, and on trunks and branches. Specific information on its diet is largely lacking. Only a handful of nests have been reported and details on breeding biology absent.

Threats
This species may be developing resistance to avian malaria and pox, but clearing of habitat, depredation from feral mammal populations, and habitat degredation from invasive plants are possible threats, as with other native Hawaiian birds. The species needs further research to understand it population dynamics and potential limiting factors.

Conservation
More research into the species biology and factors regulating its populations would be helpful in order to pinpoint any unforeseen threats that could be moderated. Protection of more forested habitat and restoration of degraded habitat would benefit the species.

What Can You Do?
Volunteers are crucial to the success of programs that monitor the long-term status of populations of Oahu Amakihi and other bird species. Audubon's Christmas Bird Count (CBC) is one of the longest-running citizen-science monitoring programs in the world and has helped to follow changes in the numbers and distribution of Oahu 'Amakihi . To learn more about the CBC and how you can participate, visit: http://www.audubon.org/bird/cbc

Join Hawaii Audubon Society. A chapter of National Audubon, the Hawaii Audubon Society works to protect and educate people about Hawaii's birds. For more information visit: http://www.audubon.org/states/hi/

Support efforts to control feral animals and invasive plants and insects throughout the Hawaiian Islands. For more information visit: http://www.hear.org/

Support efforts to protect native forest habitat on Oahu by state and federal agencies and conservation organizations.

References
BirdLife International. 2000. Threatened Birds of the World. Lynx Edicions and BirdLife International, Barcelona and Cambridge, UK.

Lindsey, G. D. et. al. 1998. Hawaii 'Amakihi (Hemignathus virens), Kaua'i 'Amakihi (Hemignathus kauaiensis), Oahu 'Amakihi (Hemignathus chloris), Greater 'Amakihi (Hemignathus sagittirostris). In The Birds of North America, No. 360 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologist's Union, Washington, D.C.

Pratt, H. D. et. al. 1987. A Field Guide to the Birds of Hawaii and the Tropical Pacific. Princeton UP, Princeton, New Jersey.