The word Luscinia was used for nightingales and similar birds in Classical Latin, if not earlier. Etymologically, it might be derived from luscus or clueō + Latincanō "to sing". Hence, it could be translated as "little-seen songster" or "famous songster". The genusLuscinia was introduced by the English naturalist Thomas Forster in 1817. The type species is the common nightingale. Delimitation of Luscinia versus the genus Erithacus had been confused for long; species were rather indiscriminately placed in one or the other genus, or Luscinia was entirely merged into Erithacus. The genus Luscinia previously included many more species. A large molecular phylogenetic study published in 2010 found that the genus did not represent a monophyletic group. Species were therefore reassigned to other genera leaving only three species remaining in the original genus. The same study showed that the white-bellied redstart, previously placed in the monotypicHodgsonius, belonged to the same clade. The species currently placed in Luscinia are:
The Luscinia species are stocky small birds, 13–16 cm long with an upright stance and a moderately short frequently cocked tail. They watch for insects, worms and other invertebrates from a low perch, and feed mostly on the ground, hopping, with frequent stops, on their strong legs. They are territorial during the breeding season, and most occur as far north as to be migratory. In the two species named as nightingales, the sexes are similar. They are plain brown above, whitish below with light streaking, and have a rufous tail. In the other Luscinia species, the male is much brighter than the cryptic, usually brownish-grey female. Males have a dark blue, black or brown back, and red, orange or blue on the throat and upper breast. Several have white or rufous patches on the sides of the tail, giving a pattern recalling that of the closely related wheatear, or some of the less closely related Muscicapinae. The songs of this genus are often complex and musical, especially in the "typical" nightingales. They are birds of Eurasia, occurring from the subarctic to the tropical regions. They are plentiful in temperate regions, and many of the birds in this genus are strongly migratory, wintering in tropicalAfrica, India or Southeast Asia. The breeding habitat is typically scrub or forest, and their cup nest is usually constructed low in a bush. The birds can be difficult to see in dense undergrowth, especially if not singing, but they may frequent somewhat more open habitats in their winter quarters.