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"
Red-throated thrush Red-throated thrush The red-throated thrush ("Turdus ruficollis") is a passerine bird in the thrush family. It is sometimes regarded as one subspecies of a polytypic species, "dark-throated thrush", black-throated thrush then being the other subspecies. More recent treatments regard the two as separate species. The scientific name comes from Latin. "Turdus" is "thrush" and the specific "ruficollis" is derived from "rufus', "red", and "collum", "neck". The red-throated thrush is a migratory Asian species. Its range overlaps with the more westerly-breeding black-throated thrush. It is a large thrush with a plain grey back and reddish underwings. The adult male has a