Zosterops (meaning "eye-girdle") is a genus of passerine birds containing the typical white-eyes in the white-eye family Zosteropidae. The genus has the largest number of species in the white-eye family. They occur in the Afrotropical, Indomalayan, and Australasian realms. Typical white-eyes have a length of between 8 and 15 cm (3 and 6 in). Their most characteristic feature is a conspicuous white feather ring around the eye, though some species lack it. The species in this group vary in the structural adaptations of the tongue.[1] The Zosterops [griseotinctus] group is an example of a "great speciator" inhabiting a vast area and showing a remarkable morphological differentiation on islands, some of which maybe as close as 2 km (1.2 mi) apart.[2]
The genus Zosterops was introduced by the naturalists Nicholas Vigors and Thomas Horsfield in 1827.[3] The name combines the Ancient Greek words zōstēros "belt" or "girdle" and ōpos "eye".[4] The type species was designated as the Malagasy white-eye by René Lesson in 1828.[5][6]
The results of a series of molecular phylogenetic studies published between 2014 and 2018 prompted a major revision of species limits, in which 10 new genera were introduced. In the reorganisation, the English names of three of the existing genera were replaced.[7][8][9][10][11]
Additionally, a study on Sri Lanka white-eyes (Zosterops ceylonensis) and Indian white-eyes (Zosterops palpebrosus) suggests that the Sri Lanka white-eye is the root species and the origin of all Zosterops species.[12] This raises questions upon the former theory of Southeast Asian origin.
There are over 100 species in the genus. This includes three species (denoted by a dagger † in the list below) that have become extinct since the 16th century.[11]