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"
Olive thrush Olive thrush The olive thrush ("Turdus olivaceus") is, in its range, one of the most common members of the thrush family (Turdidae). It occurs in east African highlands from Tanzania and Zimbabwe in the north to the Cape of Good Hope in south. It is a bird of forest and woodland, but has locally adapted to parks and large gardens in suburban areas. In 1760 the French zoologist Mathurin Jacques Brisson included a description of the olive thrush in his "Ornithologie" based on a specimen collected from the Cape of Good Hope in South Africa. He used the French name