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"
Orange-headed thrush band. Calls of the orange-headed thrush include a soft "chuk" or "tchuk", a screeching "teer-teer-teer", and a thin "tsee" or "dzef" given in flight. However, this bird is generally silent especially in winter. The song is a loud clear series of variably sweet lilting musical notes, recalling the quality of the common blackbird, but with the more repetitive structure of the song thrush. It also includes imitations of other birds like bulbuls, babblers and common tailorbird. It sings from a perch in a leafy tree, mostly early morning and late afternoon. The orange-headed thrush is a shy, secretive bird usually