The Kauai ʻakialoa (''Akialoa stejnegeri'') is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species of

Hawaiian honeycreeper Hawaiian honeycreepers are a group of small birds endemic to Hawaii. They are members of the finch family Fringillidae, closely related to the rosefinches (''Carpodacus''), but many species have evolved features unlike those present in any othe ...

in the subfamily

Carduelinae The cardueline finches are a subfamily, Carduelinae, one of three subfamilies of the finch family Fringillidae, the others being the Fringillinae and the Euphoniinae. The Hawaiian honeycreepers are now included in this subfamily. Except for the ...

of the family

Fringillidae The true finches are small to medium-sized passerine birds in the family Fringillidae. Finches generally have stout conical bills adapted for eating seeds and nuts and often have colourful plumage. They occupy a great range of habitats where the ...

. It was

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the island of

Kauai Kauai (), anglicized as Kauai ( or ), is one of the main Hawaiian Islands. It has an area of 562.3 square miles (1,456.4 km2), making it the fourth-largest of the islands and the 21st-largest island in the United States. Kauai lies 73 m ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

, and became extinct in the 20th century due to introduced avian disease and

habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

. The Kauai ʻakialoa was about seven and a half inches in length and had a very long downcurved bill, which covered one third of its length. The adult males were bright olive-yellow on top and yellow on the bottom. The throat, breast, and sides of the body were olive-yellow. The females, however, were green-gray above and had a shorter bill.

Habitat and behavior

The Kauai ʻakialoa was believed to have lived in forests above above sea level, but was frequently observed flying to the lower elevations of the island. This once very rare and unique bird used its long curved bill to reach the nectar of ''

lobelia ''Lobelia'' () is a genus of flowering plants in the family Campanulaceae comprising 415 species, with a subcosmopolitan distribution primarily in tropical to warm temperate regions of the world, a few species extending into cooler temperate r ...

s'' and '' ʻohiʻa'' blossoms. It also ate insects from under tree bark and from under mats of lichens and moss on trees.

Acanthocephala Acanthocephala ( Greek , ' 'thorn' + , ' 'head') is a group of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses t ...

n parasite ''

Apororhynchus hemignathi ''Apororhynchus'' is a genus of small parasitic spiny-headed (or thorny-headed) worms. It is the only genus in the family Apororhynchidae, which in turn is the only member of the order Apororhynchida. A lack of features commonly found in the phy ...

'' was discovered in the intestine of the Kauaʻi ʻakialoa in 1896.

Past and present

The Kauai ʻakialoa, like all the other ʻakialoa subspecies (now all raised to species), was rare even when it was first discovered in the 18th century. According to fossil records, their numbers declined extremely in the early 20th century. The typical habitats for the Kauai ʻakialoa were either tropical lowlands or moist

montane forest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

s of the Hawaiian Islands. Many people believe that the bird's frequent ventures to lower elevations were its undoing, possibly due to a low elevation avian disease. An invasive species of mosquito, the possible

disease vector In epidemiology, a disease vector is any living agent that carries and transmits an infectious pathogen such as a parasite or microbe, to another living organism. Agents regarded as vectors are mostly blood-sucking ( hematophagous) arthropods such ...

which led to demise of the ʻakialoa, was first introduced via whaling ships in 1826. The insects tended to prefer low elevation, moist environments, and seasonally warm temperatures, which is the conditions in which ʻakialoa birds were found. These mosquitoes were carrying a type of malaria which infected and killed a majority of the ʻakialoa birds, thus beginning the slow demise of the species, as well as many other Hawaiian species. The last documented Kauai ʻakialoa was seen in 1967. ʻAkialoa were once known on all of the other larger Hawaiian islands, but the Kauai species seems to have outlived all the rest. Unfortunately, scientists fear that even this bird might have gone extinct. Because these birds were so rare, not much is known about their life history. Changes to low-elevation ecosystems caused the downfall of many if not all major forest birds on Kauai. These changes began when the first

Polynesians Polynesians are an ethnolinguistic group comprising closely related ethnic groups native to Polynesia, which encompasses the islands within the Polynesian Triangle in the Pacific Ocean. They trace their early prehistoric origins to Island Sout ...

settled on the island and logged and cleared some of the arable land for crops. With new settlers, invasive plants and animals entered the Hawaiian Islands. Today, only about of Kauai have not been drastically altered. Many avian diseases and parasites also pose a major threat to Hawaii's forest birds. Dramatic forest fires on the islands in the past caused further

habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

for the Kauai ʻakialoa.

Conservation efforts

The Forest Reserve Act of 1903 was created to protect the forests and river watersheds on the island. In 1907, the Hawaiian Territorial Legislature passed a law to protect all native perching birds. In 1964, two scientists, F. Richardson and J. Bowles, published a survey of the birds of Kauai and introduced the world to these beautiful birds' fragile existence. The Kauai ʻakialoa was registered as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

in 1967 under the federal

Endangered Species Act The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting and conserving imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...

. The service began bird surveys on Kauai from 1968 to 1973. Extensive work on the puaiohi, another rare Kauai forest bird, has yielded no sightings of the Kauai ʻakialoa. In September 2021, the U.S. Fish and Wildlife Service proposed declaring the Kauaʻi ʻakialoa extinct, following the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

. In October 2023, the species was delisted from the Endangered Species Act citing extinction.

References

{{Taxonbar, from1=Q41000174, from2=Q4251311, from3=Q27075764

Extinct birds of Hawaii Kauai Akialoa Kauai Akialoa Bird extinctions since 1500 Taxonomy articles created by Polbot Kauai Akialoa