Hematologie a krevni parazite volne zijicich ptaku.

It is very difficult to determine physiological values of haematological parameters for wild birds. The results of blood examinations can be influenced by many factors. The total health condition of birds is the main factor, but also stress can influence the results. The birds are stressed by their catching and short-term keeping in captivity and also by bleeding It is also known that haematological values of wild birds depend on age and sex of examined birds and that they are changing in relation to year season and food uptake. But there is no evidence of negative influence of bleeding for their next life or reproduction. The prevalence and intensity of infection with blood parasites were determined in five bird species: Erithacus rubecula, Sylvia atricapilla, Parus major, Carduelis chloris and Coccothraustes coccothraustes. Only two examined birds showed signs of impaired health condition. It is supposed that blood parasites did not cause strong pathological changes in wild birds. The only recorded negative influence of parasites in birds was the increasing of intensity of Haemoproteus infection as a result of concurrent Leucocytozoon infection. Parasites of genus Leucocytozoon are considered to be the most pathogenic blood protozoa for birds. But only a small number of birds with mixed infection were examined, therefore this finding sholud be further studied to confirm it.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Blood parasites (Haemoproteus and microfilariae) in birds from the Caribbean slope of Costa Rica

We studied blood parasites in wild birds within Hitoy Cerere Biological Reserve and Barbilla National Park in Costa Rica during the rainy season of 2004. We examined blood samples from 248 and 114 birds, respectively. Protozoan parasites of the genus Haemoproteus as well as microfilariae were found. Prevalence of Haemoproteus in birds was 0. 8% and 4. 4% in Hitoy Cerere and Barbilla, respectively, and differences were significant. Prevalence of infection by microfilariae was 8. 1% and 3. 5%, respectively, however, differences were not significant. Based on morphological characteristics, we divided microfilariae into two groups and nine morphotypes. In Hitoy Cerere, there were microfilariae of all nine morphotypes whereas in Barbilla we only found two morphotypes