Abstract
DNA-based identification of birds has become routine and presents enormous possibilities for expanding our knowledge of identification, migration patterns and breeding ranges. This paper has been written to explain the theoretical background of DNA-based identification, to attempt to demystify the process, and to provide practical information useful for birders and ringers. To illustrate the versatility and usefulness of DNA-based identification, three examples are used: Britain’s potential first records of ‘Caspian Reed Warbler’ Acrocephalus scirpaceus fuscus and Acadian Flycatcher Empidonax virescens, and multiple records of migrant Lesser Whitethroats Sylvia curruca demonstrating the regular occurrence of both S. c. blythi and S. c. halimodendri. It is argued that DNA-based identification augments but does not replace ‘proper’ birding skills.