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"
Tristan thrush Tristan thrush The Tristan thrush ("Turdus eremita"), also known as the starchy, is a species of bird in the thrush family that is endemic to the British overseas territories of the isolated Tristan da Cunha archipelago in the South Atlantic Ocean. The bird was described by John Gould as being similar in size and appearance to the song thrush, and by Henry Moseley as like a very dark-coloured song thrush. However, it also has the short rounded wings and reduced keel indicative of a reduced need for flight, typical of bird species adapted to life on small islands. This thrush