Impact of Forest Degradation on Breeding Birds of the Talysh Mountains in the Azerbaijan Republic

The Talysh Mountains in Azerbaijan are covered with deciduous broadleaf forests. Currently they are suffering ongoing forest degradation. The response of the local fauna to forest degradation is unknown. In this study breeding birds act as bioindicators and their response can reflect response of other taxonomic groups in this area. For the study I used the Line Transect method and surveyed 66.8 km of different forest degradation stages. I found 70 breeding bird species. Forest-dependent bird species showed a negative response to forest degradation, whereas open-land species were responding positively. The heavily degraded forests with a park-like or shrubby appearance show the highest number of bird species. The reason for this pattern is the horizontal vegetation structure in degraded forests, which are highly heterogeneous and thus forest-dependent and open-land species can breed here. Furthermore, I found the highest number of forest-dependent species in natural and slightly disturbed forests. Fourteen of them showed a significant negative response and are likely to become extinct with ongoing degradations.