Анализ фаунистического сходства сообществ пернатых хищников некоторых местообитаний Алтайского края и республики Алтай

Abstract

Birds of the orders Falconiformes, Accipitriformes, and Strigiformes are at the top of the food chain, and therefore, they are the most vulnerable to changes in the natural environment caused by human activities. The condition of populations of birds of prey can serve as a criterion for the well-being of a biotope. The current state of nesting groups of many species of birds of prey in Altai Krai is of great concern. The survival of many of them is now in question, as numerous threats are generated by lumbering, mining, farming, poaching, growing energy infrastructure, and other human activities. In this regard, there is an urgent need for a detailed study of the species composition and population numbers of birds of prey and owls in the Altai region, as well as regular monitoring of populations that still exist. In this paper, we made a comparative analysis of breeding groups of raptors of different habitats of the Russian part of the Altai region: the Ukok plateau, the Ulandryk River gorge, the Anui River valley and the Kasmalinsky pine forest. Data on the species composition are taken from both our works and literature. We carried out a comparative analysis of breeding groups of birds using the coefficients of faunistic similarity of Jaccard and Sörensen. Since we had to compare more than two breeding groups, we used Mountford cluster analysis to order the similarity coefficients, which consists in sequentially combining the most similar groups. The results of the analysis of the Jaccard and Sörensen coefficients turned out to be very similar. The greatest similarity of the nesting species composition was found between the Anui River valley and Kasmalinsky pine forest (Кj=0.63; Кs=0.77). More significant differences were found between the Ukok plateau and the Ulandryk River gorge (Кj=0.44; Кs=0.60). And the maximum differences were found between the Kasmalinsky pine forest and the Ulandryk gorge (Кj=0.17; Кs=0.29). These differences can be explained by the specifics of the physical and geographical conditions and vegetation cover of different habitats of the Altai region. The poor species composition of raptors in the Ulandryk Gorge (7 species of birds of prey and 1 species of owls) is due to the complete absence of woods in this habitat. Therefore, there are no tree-nesting species here. The gorge is inhabited only by those species of raptors that can build their nests on the rocks. There are also no species here that require special types of prey, which are not sufficient in this biotope. The richness of the species composition of raptors (18 species of birds of prey and 8 species of owls) in the Kasmalinsky pine forest is because most species are dendrophiles and find here the optimal substrate for nests – large pines. The forage base here is also optimal for most species of raptors. Only specific mountain-steppe and high-mountain species do not nest in the pine forest. According to the species composition of raptors, habitats such as the Ukok plateau and the Anui river valley are in an intermediate position between the Ulandryk gorge and the Kasmalinsky pine forest. Both have rocky outcrops suitable for nesting and trees. Therefore, in these biotopes birds that prefer nesting both on rocks and in trees can be found.