Song thrush thrush recognizes the cuckoo's non-mimetic eggs. However, the song thrush does not demonstrate the same aggression toward the adult cuckoo that is shown by the blackbird. The introduced birds in New Zealand, where the cuckoo does not occur, have, over the past 130 years, retained the ability to recognise and reject non-mimetic eggs. Adult birds may be killed by cats, little owls and sparrowhawks, and eggs and nestlings are taken by magpies, jays, and, where present, grey squirrels. As with other passerine birds, parasites are common, and include endoparasites, such as the nematode "Splendidofilaria (Avifilaria) mavis" whose specific name "mavis"
Naumann's thrush female is fairly similar to the male, but immatures have a weaker patterning. The song of Naumann's thrush may differ from the simple fluted or whistling redwing-like song of dusky thrush. The genus name comes from Latin "Turdus", "thrush", and the species and English names commemorate the German naturalist Johann Andreas Naumann. Naumann's thrush Naumann's thrush ("Turdus naumanni") is a member of the thrush family Turdidae which breeds eastwards from central Siberia. It is closely related to the more northerly breeding dusky thrush "T. eunomus"; the two have often been regarded as conspecific. This species breeds in open woodland areas;