Information about the Bird Iiwi
The iiwi (Drepanis coccinea, pronounced /iivi/, ee-EE-vee), or scarlet honeycreeper is a "hummingbird-niched" species of Hawaiian honeycreeper. It is one of the most plentiful species of this family, many of which are endangered or extinct. The iiwi is a highly recognizable symbol of Hawaii. The iiwi is the third most common native land bird in the Hawaiian Islands. Large colonies of iiwi inhabit the islands of Hawaii, Maui, and Kauai, with smaller colonies on Molokai and Oahu but are no longer present on Lnai. Altogether, the remaining populations total 350,000 individuals, but are decreasing.
The adult iiwi is mostly scarlet, with black wings and tail and a long, curved, salmon-colored bill used primarily for drinking nectar. The contrast of the red and black plumage with surrounding green foliage makes the iiwi one of Hawaii's most easily seen birds. Younger birds have golden plumage with more spots and ivory bills and were mistaken for a different species by early naturalists. Observations of young birds moulting into adult plumage resolved this confusion.
Although it was used in the feather trade, it was less affected than the Hawaii mamo because it was not as sacred to Hawaiians. The iiwi's feathers were highly prized by Hawaiian alii (nobility) for use in decorating ahuula (feather cloaks) and mahiole (feathered helmets), and such uses gave the species its original scientific name: Vestiaria, which comes from the Latin for "clothing", and coccinea meaning "scarlet-colored". (In 2015 the IOC World Bird List moved the iiwi from genus Vestiaria to Drepanis, from the Greek for sickle, a reference to the shape of the beak.)
The bird is often mentioned in Hawaiian folklore. The Hawaiian song "Sweet Lei Mamo" includes the line "The i'iwi bird, too, is a friend".
The bird can hover, much like a hummingbird. Its peculiar song consists of a couple of whistles, the sound of balls dropping in water, the rubbing of balloons together, and the squeaking of a rusty hinge.
The long bill of the iiwi assists it to extract nectar from the flowers of the Hawaiian lobelioids, which have decurved corollas. Starting in 1902 the lobelioid population declined dramatically, and the iiwi shifted to nectar from the blossoms of hia lehua (Metrosideros polymorpha) trees.Iiwi also eat small arthropods.
These birds are altitudinal migrants; they follow the progress of flowers as they develop at increasing altitudes throughout the year. Seeking food at low elevation exposes them to low elevation disease organisms and high mortality. Because the iiwi can migrate between islands, it has not gone extinct on smaller islands such as Molokai.
In the early winter in January to June, the birds pair off and mate as the hia plants reach their flowering maximum. The female lays two to three eggs in a small cup shaped nest made from tree fibers, petals, and down feathers. These bluish eggs hatch in fourteen days. The chicks are yellowish-green marked with brownish-orange. The chicks fledge in 24 days and soon attain adult plumage.
Linguists derive the Hawaiian language word iiwi from Proto-Nuclear-Polynesian *kiwi, which in central Polynesia refers to the bristle-thighed curlew (Numenius tahitiensis), a migratory bird. The long decurved bill of the curlew somewhat resembles that of the iiwi.
Although iiwi are still fairly common on most of the Hawaiian islands, they are rare on Oahu and Molokai and since 1929 no longer found on Lnai. Most of the decline was from loss of habitat, as native forests were cleared for farming, grazing, and development.
Plentiful in two parts of its range, it is listed as a threatened species because of small populations in some of its range and its susceptibility to fowlpox and avian influenza. Ninety percent of all exposed iiwi died and the other ten percent were weakened but survived. Habitat restoration projects removed non-native/invasive plants and animal species, including on the Island of Hawaii, around Mauna Kea. Smaller lobelia populations forced iiwi to target hia trees.
Introduced diseases, particularly avian malaria (Plasmodium relictum) are spread by mosquitoes. In a series of challenge experiments involving avian malaria, more than half of the iiwi tested died from a single infected mosquito bite. Iiwi generally survive at higher elevations where temperatures are too cool for mosquitoes. Many disease-susceptible endemic birds became rare to absent at lower elevations, even in relatively intact native forest. The iiwi were also removed when forests were replaced with farms, plantations, towns, and alien forests.
Altitudinal migration complications population assessment.
On Molokai, The Nature Conservancy preserved habitat by fencing off areas within several nature reserves to keep out pig populations. The pigs create wallows which serve as incubator sites for mosquito larvae, which in turn spread avian malaria.
Iiwi was formerly classified as a near threatened species by the IUCN, but recent research has proven that it was rarer than previously believed. Consequently, it was uplisted to vulnerable status in 2008.
More inforamtion about Iiwi.