Life in the extreme environment: Structure and species richness of bird assemblages on Yuzhny Island of Novaya Zemlya, Russia

Abstract

Birds play a vital role in arctic environments, being multi-functional ecosystem engineers, but these animals are heavily impacted by recent climate warming. Bird assemblages on the Arctic Ocean archipelagoes are poorly known, because many such areas are hardly accessible to scientists. Novaya Zemlya, one of the most enigmatic places in the World, was a closed military area from the late 1940s. This gigantic mountainous archipelago can be considered a terra incognita by means of modern faunal, taxonomic, and ecological research. In the present study, we provide the first qualitative data on bird assemblages of the Yuzhny Island of Novaya Zemlya, estimate the diversity of bird species through a range of habitats, and underscore environmental factors determining the spatial distribution of avifauna in the arctic tundra biome. In terrestrial habitats, Tundra Bean Goose (Anser fabalis rossicus), Barnacle Goose (Branta leucopsis) and Snow Bunting (Plectrophenax nivalis) were the most abundant species. In freshwater and coastal marine habitats, both these Arctic-breeding goose taxa, and Black-legged Kittiwake (Rissa tridactyla), Common Eider (Somateria mollissima) and Thick-billed Murre (Uria lomvia) were the dominant species. The most species-rich bird assemblages (11-15 species) were associated with willow tundra, freshwater lakes, and coastal sea habitats, while only a few species were recorded in dry rocky habitats, open sea environments, and littoral areas of lakes and the sea. Mountain rocky heathlands covering most of the area of Yuzhny Island were scarcely populated by birds, with only a few species recorded frequently there, such as the Rough-legged Buzzard (Buteo lagopus) and Snow Bunting. Our findings highlight that the bird assemblages on Novaya Zemlya share low species richness and that these assemblages contain a large proportion of sea and shore bird species even in terrestrial habitats. Among the terrestrial birds, only four cold-tolerant, common species successfully colonize these extreme environments during the short summer season.