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

Old World warbler The Old World warblers are a large group of birds formerly grouped together in the bird family Sylviidae. They are not closely related to the New World warblers. The family held over 400 species in over 70 genera, and were the source of much taxo ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 pl ...

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

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

Taxonomy

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

nominate subspecies In biological classification, subspecies (: 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. ...

, the Laysan millerbird, became

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 ...

sometime between 1916 and 1923. The other, the critically endangered Nīhoa millerbird, is the only race left, inhabiting the small island of Nīhoa in

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 ...

, though it has since been reintroduced to

Laysan Laysan (; ) is one of the Northwestern Hawaiian Islands, located northwest of Honolulu. It has one land mass of , about in size. It is an atoll of sorts, although the land completely surrounds Laysan Lake, some above sea level, that has a sa ...

. It is the only Old World warbler to have colonised

, and 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 preserve ...

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 young and potentially a lifelong bond. Pair-bonding is a term coined in the 1940s that is frequently ...

s and defend

territories A territory is an area of land, sea, or space, belonging or connected to a particular country, person, or animal. In international politics, a territory is usually a geographic area which has not been granted the powers of self-government, ...

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 Nīhoa 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 Nīhoa 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