Determination of Dispersal Corridors Used by Large Mammals Between Close Habitats

Abstract

In recent years, due to the expansion of cities, the transformation of agricultural areas, the forestry activities carried out solely for wood production, and the spread of transportation networks, natural habitats have become increasingly fragmented, and suitable habitats for wildlife are rapidly decreasing. As a result, natural areas are being divided, connections are being cut off, species’ living spaces are shrinking, and species and habitats are being isolated. This fragmentation significantly hinders the natural movements of large mammals (Ursus arctos, Sus scrofa, and Canis lupus), leading to reduced genetic diversity and threatening the long-term viability of their populations. This research, conducted in the Ballıdağ and Kurtgirmez regions of the Western Black Sea Region of Türkiye, aimed to determine the movement corridors of the brown bear (Ursus arctos), wild boar (Sus scrofa), and wolf (Canis lupus) in the area and to evaluate the habitat connections for these species. This study relied on data obtained through field studies and the previous literature. Ecological modeling was used with the Maximum Entropy Method (MaxEnt) to understand the relationships between these species and environmental variables, and the barriers posed by the latter. Ecological corridor maps were created to evaluate the effects of habitat fragmentation in the region and species’ potential to maintain critical connection points despite this fragmentation using Circuitscape software based on the Circuit Theory approach. As a result of the analysis, it was determined that the AUC values were between 0.75 and 0.8; the most important variables in the models were road density, vegetation, and elevation; focal points and resistance surface areas were determined for three large mammal species; and important ecological corridors were defined between the Ballıdağ and Kurtgirmez regions. This study revealed that preserving habitat connections and reducing fragmentation is critical for the long-term existence of predator species and ecosystem health.