The mountain chiffchaff or eastern chiffchaff (''Phylloscopus sindianus'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

leaf warbler Leaf warblers are small insectivorous passerine birds belonging to the genus ''Phylloscopus''. Leaf warblers were formerly included in the Old World warbler family but are now considered to belong to the family Phylloscopidae, introduced in 20 ...

found in the

Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historically ...

(''P. s. lorenzii'') and Himalayas (''P. s. sindianus''), and is an altitudinal migrant, moving to lower levels in winter. The nominate subspecies is similar to the Siberian chiffchaff, but with a finer darker bill, browner upperparts and buff flanks; its song is almost identical to the

common chiffchaff The common chiffchaff (''Phylloscopus collybita''), or simply the chiffchaff, is a common and widespread leaf warbler which breeds in open woodlands throughout northern and temperate Europe and the Palearctic. It is a migratory passerine which ...

, but the call is a weak ''psew''. ''P. s. lorenzii'' is warmer and darker brown than the nominate race; it is sympatric with common chiffchaff in a small area in the Western Caucasus, but interbreeding occurs rarely, if ever. The mountain chiffchaff differs from ''tristis'' in vocalisations, external morphology and

mtDNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA ...

sequences. Its two subspecies appear to be distinct vocally, and also show some difference in mtDNA sequences.

References

*(German) Martens, Jochen (1982): Ringförmige Arealüberschneidung und Artbildung beim Zilpzalp, Phylloscopus collybita. Das lorenzii-Problem. Zeitschrift für Zoologische Systematik und Evolutionsforschung 20: 82–100. *German) Martens, Jochen; Hänel, Sabine (1981): Gesangformen und Verwandtschaft der asiatischen Zilpzalpe Phylloscopus collybita abietinus und Ph. c. sindianus. Journal für Ornithologie 122 (4): 403–427. ith English abstractdoi:10.1007/BF01652928 *Sangster, George; Knox, Alan G.; Helbig, Andreas J.; Parkin, David T. (2002). "Taxonomic recommendations for European birds". Ibis 144 (1): 153–159. doi:10.1046/j.0019-1019.2001.00026.x. https://doi.org/10.1046/j.0019-1019.2001.00026.x *Helbig, Andreas J.; Martens, Jochen; Seibold, I.; Henning, F.; Schottler, B; Wink, Michael (1996). "Phylogeny and species limits in the Palearctic Chiffchaff Phylloscopus collybita complex: mitochondrial genetic differentiation and bioacoustic evidence". Ibis 138 (4): 650–666. http://www.uni-heidelberg.de/institute/fak14/ipmb/phazb/pubwink/1996/13_1996.pdf. mountain chiffchaff Birds of Azerbaijan Birds of Central Asia Birds of North India Birds of Western China mountain chiffchaff {{Phylloscopidae-stub