Hume’s Whitethroat, Sylvia althaea, is a species of typical warbler.
Until recently, it was considered conspecific (of, or belonging to, the same species) with the Lesser Whitethroat; today these are seen as members of a superspecies which also includes the Small Whitethroat.
The present species together with the aridland Small Whitethroat(s) seems to form an Asian lineage in the superspecies.(Helbig 2001, Jønsson and Fjeldså 2006)
It is distinguished from the Lesser Whitethroat by its darker top of the head and browner back, which results in coloration of the entire upper head-to-back region that does not have strong contrasts.
Their ranges do not seem to overlap; Hume’s Whitethroat inhabits upland regions of Iran and northeastwards into Central Asia to the western reaches of the Himalayas.
No subspecies are currently recognized by most authors. From the Balkans to the Caucasus Mountains however, Sylvia curruca caucasica occurs which is intermediate between the Lesser and Hume’s Whitethroats (Snow et al. 1998).
It is presently not clear whether the eastern part of this population is correctly assigned to the European species, or consists of hybrids in a contact zone.
