The mycology of swabs collected from the beak and the cloaca in 4 species of mud and water waders, migrating through various climatic zones,was analysed. Diagnostic standards were used 54 isolates of fungi belonging to 5 genera: Aspergillus - 53.9%, <i>Rhodotorula</i> - 19.6%, <i>Candida</i> - 14.8%, <i>Saccharomyces</i> - 6.9%, and <i>Torulopsis</i> - 4.8%, were obtained. A total number of 15 species of which <i>Aspergillus fumigatus</i> and <i>A.flavus</i> as well as <i>Candida albicans</i>, <i>C. tropicalis</i> and <i>C. glabrata</i> are of the greatest significance in epidemiology of mycoses, was recorded. Numerous fungi were isolated from the cloaca, which indicates that the birds examined are carriers and suggasts that they may take an active part in thc transmission of fungi that arc dangerous for humans and that colonise water reservoirs.

The paper presents mycological studies conducted jointly with ornithologists on the epidemiology of mycoses and the taxonomic diversity and prevalence of fungi that colonise the selected onthocenoses in healthy, wild migratory birds. Aquatic ecosystem populations of healthy birds include a percentage of carriers of potential zoo-and anthropopathogens, and this study's purpose was to determine the percentage. The studies were performed on swabs sampled in vivo (during spring and autumn migrations) from the beak and cloaca of nine species of Charadriiformes in two age categories. Macro-and microcultures of fungi were prepared according to the standards for diagnostic mycological laboratories. From the 450 birds examined, fungi were isolated from 130 (26.5%) individuals. The sampling yielded 272 yeast isolates: 170 (62.5%) from the beak and 102 (37.5%) from the cloaca. The isolates represented 23 species, among which C. albicans, C. neoformans, and R. rubra were predominant. In both onthocenoses in young and adult birds, more fungi were recorded in autumn than in spring. As many as 15 species are included in the biosafety level classification, of which seven are categorised as category 2 and one as category 3.