TheAcrocephalus warblers are small, insectivorouspasserinebirds belonging to the genusAcrocephalus. Formerly in theparaphyleticOld World warbler assemblage, they are now separated as the namesake of the marsh and tree warbler familyAcrocephalidae. They are sometimes calledmarsh warblers orreed warblers, but this invites confusion withmarsh warbler andreed warbler.
These are rather drab brownish warblers usually associated withmarshes or other wetlands. Some are streaked, others plain. Many species breeding in temperate regions aremigratory.
This genus has heavily diversified into many species throughout islands across the tropicalPacific. This in turn has led to many of the resulting insularendemic species to becomeendangered. Several of these species (including all but one of the species endemic to theMarianas and two endemic toFrench Polynesia) have already goneextinct.
The most enigmatic species of the genus, thelarge-billed reed warbler (A. orinus), was rediscovered inThailand in March, 2006; it was found also in a remote corner ofAfghanistan in the summer of 2009. Prior to these recent sightings, it had been found only once before, in 1867.
The genusAcrocephalus was introduced in 1811 by the German naturalistJohann Andreas Naumann and his sonJohann Friedrich Naumann.[2][3] Thetype species was designated asTurdus arundinaceusLinnaeus, 1758, by the English zoologistGeorge Gray in 1840. This is thegreat reed warbler.[4][5] Many species have a flat head profile, which gives rise to the genus name,Acrocephalus fromAncient Greekakros, "highest", andkephale, "head". It is possible that the Naumanns thoughtakros meant "sharp-pointed".[6]
Fragmentaryfossil remains from theLate Miocene (about 11 mya) ofRudabánya (NEHungary) show someapomorphies typical of this genus.[8] Given its rather early age (mostPasserida genera are not known until thePliocene), it is not too certain that it is correctly placed here, but it is highly likely to belong to the Acrocephalidae at the least.
^"Acrocephalidae".aviansystematics.org. The Trust for Avian Systematics. Retrieved2023-07-15.
^Naumann, Johann Andreas;Naumann, Johann Friedrich (1811).Naturgeschichte der Land- und Wasser-Vögel des nördlichen Deutschlands und angränzender Länder, nach eigenen Erfahrungen entworfen, und nach dem Leben gezeichnet. Nachtrag (in German). Köthen: Self-published. p. 199.
Olsson, U.; Rguibi-Idrissi, H.; Copete, J.L.; Arroyo Matos, J.L.; Provost, P.; Amezian, M.; Alström, P.; Jiguet, F. (2016). "Mitochondrial phylogeny of the Eurasian/African reed warbler complex (Acrocephalus, Aves). Disagreement between morphological and molecular evidence and cryptic divergence: A case for resurrectingCalamoherpe ambigua Brehm 1857".Molecular Phylogenetics and Evolution.102:30–44.Bibcode:2016MolPE.102...30O.doi:10.1016/j.ympev.2016.05.026.PMID27233439.
