'I'iwi

Iiwi
['I'iwi - © Jack Jeffrey]

The 'I'iwi (Vestiaria coccinea) is a striking nectar-feeding honeycreeper (Family Fringillidae) that is usually found in wet and moderately wet forests, but may also occur in dry habitats, on five of the main Hawaiian islands. It tracks flowering 'O'hia (Metrosideros polymorpha) trees and other native Hawaiian flowers, making daily and seasonal movements across the upper slopes of Hawaii's remaining native forests to exploit nectar resources. 'I'iwi uses its robust, sickle-shaped bill to probe flowers for nectar, and it sometimes joins calling flocks of 'Apapane, 'Amakihi, other Hawaiian honeycreepers, and non-native Japanese White-eye as they track food resources. Once very abundant throughout the Hawaiian islands, the 'I'iwi is only still common on the Big Island and Maui. The Kaua'i population is declining, and on O'ahu and Molokai they are exceedingly rare (O'ahu) or likely extirpated (Molokai). Currently, the major threat to 'I'iwi is its susceptibility to avian diseases, particularly avian malaria which is carried and transmitted by introduced mosquitoes - one mosquito bite can result in death. As a result, their range has shrunk on each island to areas generally above 1500 meters elevation where the cold-intolerant mosquitoes and the protozoan that causes malaria are less frequent; a warming climate threatens to further raise this elevational threshold. In addition, introduced pigs, goats, and cattle destroy the forest understory and pigs create breeding sites for mosquitoes; introduced rats, mongoose, and feral cats depredate adults, young, and eggs, and alien invasive plants and insects threaten all native forest ecosystems. Because of the species population declines, particularly on Kaua'i, O'ahu, and Molokai, and the ever growing threats, especially of climate change, the 'I'iwi is a Bird of Conservation Concern for the US Fish and Wildlife Service, and a Focal Species for conservation action. Although uncertainty in the face of climate change is a concern, ungulate and predator control, and habitat restoration offer some hope for this and other native Hawaiian birds, at least on the highest islands. A renewed dedication to these conservation actions will be required, however.

Date: August 2009

Sources:
BirdLife International. 2009. Species factsheet: Vestiaria coccinea , Iiwi. Retrieved August 2009 from http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=8921&m=0.

Fancy, Steven G. and C. John Ralph. 1998. Iiwi (Vestiaria coccinea) , The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology. Retrieved August 2009 from http://bna.birds.cornell.edu/bna/species/327.


Species Profile from NatureServe

'I'iwi
Vestiaria coccinea

Description: A red songbird with a strongly decurved bill. A medium sized (15 cm length, 16-20 g mass), sexually monomorphic honeycreeper; adult is brilliant vermillion; wings and tail black; wings have contrasting white patch on inner secondaries; long (25-28 mm), deeply decurved, peach or salmon colored bill (Fancy and Ralph 1998).

Life History: Hawaii: fledglings have been observed February-July; peak breeding February-June (Ralph and Fancy 1994). Kauai: eggs are laid February-April; clutch size is 1-3 (usually 2). Incubation, by female (fed by male away from nest), lasts 14 days. Young are tended by both sexes, leave nest at about 3 weeks. May defend territory in flowering ohia trees. Pollinator of lobelias in at least some areas (Spieth 1966). On Hawaii, density was generally 4-7 per ha, up to 24 per ha (monthly mean); annual survival probability was 9% for hatching year, 55% for adults (Ralph and Fancy 1995).

Habitat: Forest, especially ohia, mamane, and where lobelias are present (AOU 1983). On Hawaii, most abundant where abundant ohia nectar is available; may move each day between favorable feeding areas and forest sites with better roosting conditions (Ralph and Fancy 1995). Nests at end of branch of tall ohia tree (about 4-9 m above ground), or occasionally in smaller tree such as mamane.

Distribution:

United States: HI

Status:

NatureServe Status: Global Status: G4, Global Status Last Reviewed: 03May2004, Global Status Last Changed: 04Dec1996, Rounded Global Status: G4 - Apparently Secure

Other Statuses: IUCN Red List Category: NT - Near threatened

Resources:

Species Strategy

  • Action Plan [under development]

Taxonomy Helper

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Integrated Taxonomic Information System (ITIS)

Iiwi

    Kingdom: Animalia
    Division: Chordata
    Subdivision: Vertebrata
    Class: Aves
    Order: Passeriformes
    Family: Fringillidae
    Subfamily: Drepanidinae
    Genus: Vestiaria
    Species: Vestiaria coccinea
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