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"
Song thrush as the white-faced whistling duck. The song thrush breeds in most of Europe (although not in the greater part of Iberia, lowland Italy or southern Greece), and across the Ukraine and Russia almost to Lake Baikal. It reaches to 75°N in Norway, but only to about 60°N in Siberia. Birds from Scandinavia, Eastern Europe and Russia winter around the Mediterranean, North Africa and the Middle East, but only some of the birds in the milder west of the breeding range leave their breeding areas. In Great Britain song thrushes are commonly found where there are trees and bushes. Such areas