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"
Dusky thrush Dusky thrush The dusky thrush ("Turdus eunomus") is a member of the thrush family which breeds eastwards from central Siberia. It is closely related to the more southerly breeding Naumann's thrush "T. naumanni"; the two have often been regarded as conspecific. The scientific name comes from Latin "Turdus", "thrush" and Ancient Greek "eunomos", "orderly". This species breeds in open woodland areas, but unlike Naumann's thrush, the dusky thrush is more tolerant of mountainous and tundra-edge habitats. This species is strongly migratory, wintering south to southeast Asia, principally in China and neighbouring countries. It is a rare vagrant to western Europe.