Ecological and faunistic analysis of helmints in wetland birds of Baikal Siberia: 3. Laridae

An ecological and faunistic analysis of helminths in 7 species of the Laridae of Baikal Siberia from two subfamilies (Larinae subfamily: the common gull Larus canus, the Mongolian gull Larus mongolicus, the black-headed gull Larus ridibundus and the little gull Larus minutus; Sternidae subfamily: the Caspian tern Hydroprogne caspia the common tern Sterna hirundo, the white-winged tern Chlidonias leucopterus). The research results showed a relatively high infection of these birds (about 80%, in some species even higher). 86 species of helminths from 4 classes were identified: cestodes - 20 (23.0%) species, trematodes - 52 (60.9%), nematodes - 11 (12.8%), acantocephalus - 3 (3.5%). Gulls are infected with a greater number of species (82 species) than terns (32 species). At the same time, the proportion of trematodes in helminthofauna of gulls (58.5%) is noticeably smaller than that of terns (87.5%), on the contrary, cestodes prevail in gulls (24.4%), and to to a lesser extent in terns (6.3%). Nematodes have been found only in gulls. Gulls are infected with acantocephalus less frequently. The ratio of the number of species of cestodes and trematodes in gulls and terns is noticeably different. In terns trematodes dominate over cestodes; in gulls, their ratio is relatively close. The helminth species similarity index in these two groups of birds is low (27.9-38.1%). It has been established that abundance of helminths species depends on the nature of nutrition. In predominantly piscivorous birds it is richer than in predominantly insectivorous.