Common chiffchaff and generally pale legs. Bonelli's warbler ("P. bonelli)" might be confused with the common chiffchaff subspecies "tristis", but it has a plain face and green in the wings. The common chiffchaff also has rounded wings in flight, and a diagnostic tail movement consisting of a dip, then sidewards wag, that distinguishes it from other "Phylloscopus" warblers and gives rise to the name "tailwagger" in India. Perhaps the greatest challenge is distinguishing non-singing birds of the nominate subspecies from Iberian chiffchaff in the field. In Great Britain and the Netherlands, all accepted records of vagrant Iberian chiffchaffs relate to singing males.
Hawking (birds) nighthawk does not). When different kinds of birds have the same adaptations, such similarities are not necessaily indicative of any familial relationship between bird species. Rather, they are the result of convergent evolution. Consider, for example, the marked resemblance in body size, shape, and coloration between flycatchers of several families, though these species are not closely related: the Asian brown flycatcher (of the Muscicapidae or Old World flycatcher family), Acadian flycatcher (of the Tyrannidae or tyrant flycatcher family) of the New World, and slaty monarch (of the Monarchidae or monarch flycatcher family), endemic to Fiji. All three use flycatching to