Age Dynamics of Helminth Fauna of the Herring Gull (Larus argentatus) in Kola Bay, Barents Sea

The influence of host age on the helminth fauna of the Herring Gull (Larus argentatus) captured in breeding colonies in Kola Bay in the Barents Sea was studied. The fauna of parasitic worms in flightless chicks (15 species) and adult birds (20 species) in June, as well as in fledglings (22 species) and adult birds (13 species) in September, was studied. All three bird groups shared nine species of parasitic worms. Chicks lacked the parasites circulating in freshwater ecosystems, as well as species the life cycles of which were implemented in marine coastal environments with the participation of invertebrates with hard covers as intermediate hosts. The chicks were infested by some nonspecific helminths usually parasitic in other birds, but did not occur in adult gulls. The greatest diversity of the helminth fauna was observed in the fledglings that had switched to independent feeding. Their parasitic fauna included almost all species found in adult birds, as well as some chick worms. The most likely reasons for the differences observed were the gull parents collecting food separately from the chicks, low resistance of young birds to invasions by nonspecific helminths, a varied efficiency of foraging by young and adult birds, and seasonal availability of some food resources. A certain influence on the composition and dynamics of the helminth fauna of gulls differing in age was also revealed in birds capable of using garbage as food.

Automated summary

The study demonstrated that the age of Herring Gulls affects the composition of their parasitic fauna. Chicks lack certain parasites found in adult birds, but are infested by some nonspecific helminths usually parasitic in other bird species.