Blood parasites of migrating yellow wagtails of two subspecies--Motacilla flava feldegg and Motacilla flava flava-were studied on a sample of 473 birds caught in spring and autumn periods in Bulgaria. We controlled eight "migration waves" (flocks captured in different evenings) of yellow wagtails for four parameters--average body mass, average fat level, average wing length, and average prevalence of different hematozoan species. Gametocytes or meronts of a total of six species of hematozoa belonging to three genera were identified-Haemoproteus motacillae, Haemoproteus anthi, Plasmodium relictum, Plasmodium subpraecox, Plasmodium cathemerium, and Tryponosoma avium. Mixed infections were detected in 31 cases, of which 14 were of H. anthi/H. motacillae type. Parasite species composition was similar in the two studied subspecies of M. flava. We did not find any significant differences in the overall infection prevalence or number of infecting parasites between M. f. flava and M. f. feldegg. Parasite prevalence and the number of co-infecting parasites in spring were much higher than in fall. Season had a strong influence on the prevalence of H. anthi and H. motacillae, and for both, there was a marginally significant interaction between subspecies and season, but not a season-independent influence of subspecies. Males of M. f. feldegg had a significantly higher overall blood parasite prevalence and prevalence of H. anthi than females. Sex-related differences in the prevalence of other parasites were not significant. Migration waves of yellow wagtails differed in overall infection status and in H. motacillae prevalence, but not for H. anthi prevalence. We also found significant differences in fat score, weight, and wing length between the studied migration waves of the yellow wagtails. Fat scores of birds infected with different hematozoa were lower compared with those of the non-infected birds. This only marginally was true for body weight and was not the case for wing length. Overall, infected birds were in worse condition (estimated as the residual weight after regression with wing length) compared with the non-infected birds, but after controlling for seasonal effects, the differences in condition appeared to be due to migration season and did not significantly differ between infected and non-infected birds caught in the same season.

The lesser kestrel (Falco naumanni) was considered extinct as a breeding species in Bulgaria, but recently a small breeding colony was found again in the south-eastern part of the country. Seven recent observations of flocks or solitary birds of the species in Bulgaria during the post-breeding period are presented and commented here. It is shown that the territory of the country is a regular area for post-breeding dispersal and pre-migratory feeding of lesser kestrels. The origin of these is not known, but most probably birds from the populations of the European part of Turkey, Greece, Republic of Macedonia and Albania are involved.Abstrakt: Sokol bielopazúravý (Falco naumanni) bol v Bulharsku považovaný za už nehniezdiaci druh, avšak nedávno bola v juhovýchodnej časti Bulharska nájdená jeho malá hniezdna kolónia. V príspevku je prezentovaných a komentovaných sedem aktuálnych pozorovaní skupín alebo samostatných jedincov druhu v Bulharsku v pohniezdnom období. Poukazuje to na to, že územie krajiny je druhom pravidelne využívané v období pohniezdnych potuliek a predmigračného dopĺňania zásob. Pôvod pozorovaných jedincov nie je známy, ale najpravdepodobnejšie ide o vtáky z populácií z európskej časti Turecka, z Grécka, Macedónska a Albánska.

The area of Coastal Dobrudzha in NE Bulgaria is well known for its richness of vagrants. A long-term research project was started at a location at Durankulak Lake, on the northern Black Sea Coast, aiming to obtain data on the characteristics of autumn migration of passerine birds and on the presence of vagrants there. A total of 20 mist nets with an overall length of 200 meters were set between August and October in two different habitats - reed bed and broad-leaved forest. In 2019, a total of 9344 birds of 84 species were caught and ringed. In 2020, the number of the birds caught increased to 13786 of 93 species. Vagrants such as dusky warbler (Phylloscopus fuscatus), yellow-browed warbler (Phylloscopus inornatus) and red-flanked bluetail (Tarsiger cyanurus) were captured in 2020. Detailed information about these findings is given in the present work.

The ruddy shelduck (Tadorna ferruginea) is a species of great conservation importance within its European breeding grounds. Tadorna ferruginea is included in the Red Data Book of Bulgaria (2015) in the category “Critically Endangered”. The species is qualified as “Near Threatened” in EU27 countries as a whole. Recent data from the Balkan parts of the species range indicate its considerable enlargement. During the last 10-year period, the presence status of the ruddy shelduck during winter changed from incidentally wintering in low numbers to regular and even locally abundant wintering species. The numbers of T. ferruginea migrating over the Eastern Balkans increased substantially, especially during autumn. The reasons of these expansion of the species are discussed.

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