Haematozoa of British birds VIII. Blood parasites of migrants, particularly the willow warblerPhylloscopus trochilus

Abstract

The results of a 4 yr study of hematozoa in Palearctic migrants, particularly P. trochilus, at Tring [UK] are reported. Of 379 P. trochilus examined 11.3% were infected. Haemoproteus and Leucocytozoon were observed in adult birds returning in the spring and Atoxoplasma was the only parasite occurring in juvenile birds. Observations on re-trapped birds showed that patency quickly diminished into a latent phase and emphasized further the importance of migration in acquiring most hematozoan parasites.