The ''Acrocephalus'' warblers are small, insectivorous
passerine
A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped') which includes more than half of all bird species. Sometimes known as perching birds, passerines generally have an anisodactyl arrangement of their ...
bird
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...
s belonging to the genus ''Acrocephalus''. Formerly in the
paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...
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 ...
assemblage, they are now separated as the namesake of the marsh and tree warbler family Acrocephalidae. They are sometimes called marsh warblers or reed warblers, but this invites confusion with marsh warbler and reed warbler.
These are rather drab brownish warblers usually associated with
marsh
In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p More in genera ...
es or other wetlands. Some are streaked, others plain. Many species breeding in temperate regions are migratory.
This genus has heavily diversified into many species throughout islands across the tropical
Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...
. This in turn has led to many of the resulting insular
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 ...
species to become
endangered
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 ...
. Several of these species (including all but one of the species endemic to the
Marianas
The Mariana Islands ( ; ), also simply the Marianas, are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly Volcano#Dormant and reactivated, dormant volcanic mountains in the northwestern Pacific Ocean ...
and two endemic to
French Polynesia
French Polynesia ( ; ; ) is an overseas collectivity of France and its sole #Governance, overseas country. It comprises 121 geographically dispersed islands and atolls stretching over more than in the Pacific Ocean, South Pacific Ocean. The t ...
) have already gone
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 ...
.
The most enigmatic species of the genus, the large-billed reed warbler (''A. orinus''), was rediscovered in
Thailand
Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...
in March, 2006; it was found also in a remote corner of
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan, is a landlocked country located at the crossroads of Central Asia and South Asia. It is bordered by Pakistan to the Durand Line, east and south, Iran to the Afghanistan–Iran borde ...
in the summer of 2009. Prior to these recent sightings, it had been found only once before, in 1867.
Taxonomy
The genus ''Acrocephalus'' was introduced in 1811 by the German naturalist Johann Andreas Naumann and his son
Johann Friedrich Naumann
Johann Friedrich Naumann (14 February 1780 – 15 August 1857) was a German scientist, engraver, and editor. He is regarded as the founder of scientific ornithology in Europe. He published ''The Natural History of German Birds'' (1820–1844) ...
. The
type species
In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
was designated as ''Turdus arundinaceus''
Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
, 1758, by the English zoologist George Gray in 1840. This is the great reed warbler. Many species have a flat head profile, which gives rise to the genus name, ''Acrocephalus'' from
Ancient Greek
Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...
''akros'', "highest", and ''kephale'', "head". It is possible that the Naumanns thought ''akros'' meant "sharp-pointed".
Australian reed warbler
The Australian reed warbler (''Acrocephalus australis'') is an Old World warbler in the genus ''Acrocephalus (bird), Acrocephalus'' and is the only ''Acrocephalus'' species native to Australia. It has also been observed in Papua New Guinea and ...
Moustached warbler
The moustached warbler (''Acrocephalus melanopogon'') is an Old World warbler in the genus '' Acrocephalus''. It breeds in southern Europe and southern temperate Asia with a few breeding in north-west Africa. It is partially migratory. South-wes ...
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 ...
remains from the
Late Miocene
The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...
Hungary
Hungary is a landlocked country in Central Europe. Spanning much of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia and ...
) show some
apomorph
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to ha ...
ies typical of this genus. Given its rather early age (most Passerida genera are not known until the