The millerbird (''Acrocephalus familiaris'') is a species of

Old World warbler Old World warblers are a large group of birds formerly grouped together in the bird family Sylviidae. The family held over 400 species in over 70 genera, and were the source of much taxonomic confusion. Two families were split out initially, the ci ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Acrocephalidae The Acrocephalidae (the reed warblers, marsh- and tree-warblers, or acrocephalid warblers) are a family of oscine passerine birds, in the superfamily Sylvioidea. The species in this family are usually rather large "warblers". Most are rather p ...

endemic Endemism is the state of a species being found 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 found els ...

to the

Hawaiian Islands The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost ...

Taxonomy

It has two subspecies, ''A. f. kingi'' and ''A f. familiaris''. The

nominate subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all spec ...

, the

Laysan millerbird The Laysan millerbird (''Acrocephalus familiaris familiaris'') was a subspecies of the millerbird, similar in appearance to the remaining subspecies, the Nihoa millerbird. Its dorsal side was brown, and its belly was grayish. Its name derives f ...

, became extinct sometime between 1916 and 1923. The former, the critically endangered

Nihoa millerbird The Nihoa millerbird (''Acrocephalus familiaris kingi'') is a subspecies of the millerbird. It gets its name from its preferred food, the Miller moth. The long millerbird has dark, sepia-colored feathers, white belly, and dark beak. Its natural ...

, remains the only race left, inhabiting the small island

Nihoa Nihoa (; haw, Nīhoa ), also known as Bird Island or Moku Manu, is the tallest of ten islands and atolls in the uninhabited Northwestern Hawaiian Islands (NWHI). The island is located at the southern end of the NWHI chain, southeast of ...

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only ...

, though it has since been reintroduced to

Laysan Laysan (; haw, italics=no, Kauō ), located northwest of Honolulu at , is one of the Northwestern Hawaiian Islands. It comprises one land mass of , about in size. It is an atoll of sorts, although the land completely surrounds a shallow c ...

. It is the only Old World warbler to have colonised

, although there is no

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

evidence that the species ever had a distribution beyond these two islands.

Behavior and breeding

Millerbirds form long-term

pair bond In biology, a pair bond is the strong affinity that develops in some species between a mating pair, often leading to the production and rearing of offspring and potentially a lifelong bond. Pair-bonding is a term coined in the 1940s that is freque ...

s and defend

territories A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...

over a number of years. Territories can be as large as , although is more typical. Breeding occurs variably from January to September depending on food availability.

Identification

A small warbler that occurs only on Nihoa and Laysan in the Northwestern Hawaiian Islands. It is unlikely to be confused with any other species; the only other passerines on those islands are finches. It does not occur on the main Hawaiian Islands and prefers dense, low vegetation. It is usually secretive and hard to see well, but males sometimes sing from an exposed perch. The song and calls are harsh chirps and churring.

References

* Morin, Marie P., Sheila Conant and Patrick Conant. (1997). Laysan and Nihoa Millerbird (''Acrocephalus familiaris''), ''The Birds of North America Online'' (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online

External links

BirdLife Species Factsheet.
* Acrocephalus (bird) Birds of Hawaii Endemic fauna of Hawaii Natural history of the Northwestern Hawaiian Islands Critically endangered fauna of Hawaii Birds described in 1892 {{Acrocephalidae-stub