BIRD CALLS and SONGS: Greenfinch mimicry

Several cardueline finches, for example Lesser Goldfinch and Pine Siskin, are known to include the calls of other birds in their songs. This is a male Greenfinch, singing high in a tree in the Lee Valley, Essex, UK in May. There are over a dozen different calls, including chaffinch, dunnock, blackbird and pied wagtail.