 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 derives from this thrush. A Russian study of blood parasites showed that all the fieldfares, redwings and song thrushes sampled carried haematozoans, particularly Haemoproteus and Trypanosoma. Ixodes ticks are also common, and can carry pathogens, including tick-borne encephalitis in forested areas of central and eastern Europe and Russia, and, more widely, Borrelia bacteria. Some species of Borrelia cause Lyme disease, and ground-feeding birds like the song thrush may act as a reservoir for the disease.
