Formation of the spatial structure of the bird population in High-mountainous Dagestan and the concept of preserving its avifauna

Abstract

The presented work is the concluding part of a previously published article (Vilkov 2023) and based on a mathematical analysis of the empirical material collected during route bird surveys in 1998–2021 in the High­mountainous Province of Dagestan. Based on the long­term average population density data for 96 birds nesting and likely nesting, a cluster analysis was carried out, during which the identified avifaunal communities were grouped according to the similarity of their abundance. Using correlation analysis, environmental factors were identified that determine the territorial variability of bird population abundance. Based on the estimates of the strengths of connections determined from the Jaccard­Naumov coefficients similarity data matrix, a graph was constructed that reflects the spatial structure of the bird population at the level of selected key areas. When interpreting the spatial structure of the bird population using cluster and correlation analysis data, as well as faunal and ecological ranking data, similarities between the compared avifaunal communities were revealed, and 4 main trends in bird population changes in factor space were identified. Based on the results of assessing the strength and generality of the relationships between structure­forming factors and the territorial variability of the bird population (taking into account the areas of landscapes), the most significant was the impact of afforestation, the area of open spaces and the area of residential landscapes. When interpreting spatial differences taking into account natural and anthropogenic changes, it is possible to create a predictive model of the transformation of avifaunal communities within the study area. Analysis of existing threats that have a negative impact on the number and species diversity of birds allowed developing a population management concept based on 4 strategic directions. 1. Gasification of High­Mountain Dagestan to prevent deforestation and restore the species diversity of forest birds. 2. To preserve the species diversity of meadow birds, redirect cattle grazing to areas of meadows with increased overgrowth of grassy vegetation. 3. Increase the area of fields for sowing grain crops to preserve the species diversity of granivorous birds. 4. To preserve the species diversity of birds of prey, install perches in a mosaic pattern in the fields of grain crops.