The objective of this study was to obtain primary information on the occurrence of blood parasites and intensity of infection in the Dunnock Prunella modularis in the montane region of Slovakia. Altogether 109 birds were examined during the years 2006–2010. The occurrence of Haemoproteus sp., Leucocytozoon fringillinarum and Trypanosoma sp. was documented. Blood parasite prevalences of 45% by microscopic examination and 55% by PCR diagnostics were found. The prevalence of Leucocytozoon sp. was found to be dependent on host sex with males showing a significantly higher intensity of infection with Leucocytozoon. Adult birds showed significantly higher infection prevalence than subadults. The prevalences of both Leucocytozoon sp. and Haemoproteus sp. were significantly dependent on bird age. The intensity of infection with Haemoproteus and Leucocytozoon was positively correlated and higher intensity of infection was confirmed in adult birds then in subadults birds. The prevalence of blood parasites in our samples was significantly higher in comparison to most other studies from different countries of Europe conducted at lower altitudes, indicating that the montane zone is especially favourable for the transmission of Leucocytozoon and Haemoproteus species.
As a result of a survey of 362 birds, data were accumulated concerning the influence of migration and seasonal distribution of the Protozoa of the genus Plasmodium, Haemoproteus, Leucocytozoon and Lankesterella and Microfilariae. Material for study consisted of blood films which had been collected over two years. The smears were stained with Giemsa stain and each was examined approximately twenty minutes. The monthly incidence of infections is shown in Table 1. Plasmodium was found in 8.3 per cent of all atudied birds, from March to December with the highest intensity during the summer period. The non-migratory birds were infected in 81 per cent (of all infected with Plasmodium birds). Haemoproteus was established in 6.4 per cent from April to October. In majority this protozoan was found in migratory birds (70 per cent of all infected with Haemoproteus birds). The most popular in Poland are the protozoans of the genus Lankesterella and Leucocytozoon. These two genus were found in Poland through the all years. Leucocytozoon was found in 12.4 per cent. In majority this parasite was established in birds of the family Corvidae (78.5 per cent of all infected with Leucocytozoon birds). Corvus frugilegus was caught in majority in the winter period and it was infected in 57.7 per cent. It is interesting because the birds, which are in winter in Poland were coming from north and east. Microfilariae were found through the all year and 50 per cent of Corvidae were infected with this parasite.