Taxonomy
The Common House Martin was first described by Linnaeus in his Systema Naturae in 1758 as Hirundo urbica, but was placed in its current genus Delichon by Thomas Horsfield and Frederic Moore in 1854. Delichon is an anagram of the Ancient Greek term χελιδών (chelīdōn), meaning 'swallow', and the species name urbicum (urbica until 2004, due to a misunderstanding of Latin grammar) means 'of the town' in Latin.
The Delichon genus is a recent divergence from the Barn Swallow genus Hirundo, and its three members are similar in appearance with blue upperparts, a contrasting white-rump, and whitish underparts. In the past, the Common House Martin was sometimes considered to be conspecific with the Asian House Martin (D. dasypus), which breeds in the mountains of central and eastern Asia and winters in Southeast Asia, and it also closely resembles the Nepal House Martin (D. nipalense), a resident in the mountains of southern Asia. Although the three Delichon martins are similar in appearance, only D. urbicum has a pure white rump and underparts.
The Common House Martin has two geographical subspecies, the western nominate subspecies D. u. urbicum, and the eastern D. u. lagopodum, which was described by German zoologist Peter Simon Pallas in 1811. Other races, like meridionalis from around the Mediterranean have been described, but the claimed differences from the nominate race are clinal, and therefore probably invalid.
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