Chewing lice in Azorean Blackcaps ( Sylvia atricapilla ): a contribution to parasite island syndromes.

Focusing upon chewing lice (Phthiraptera: Amblycera, Ischnocera) parasitizing blackcaps ( Sylvia atricapilla ) in the Azores (Portugal), we found a lower number of louse species in the Azores compared to mainland Europe. Only chewing lice host specific to blackcaps were found in the Azores. Louse prevalences were much higher in blackcaps from the Azores compared to those of various mainland populations. Chewing lice are permanent parasites of birds, and for such parasites the parasite island syndrome could be characterized by higher parasite prevalence on the islands compared to the mainland.