Lack of evidence for short-term structural changes in bird assemblages breeding in Mediterranean mosaics moderately perforated by a wind farm

• Wind farm turbines induce a habitat perforation in oak mosaics.
• About 10 % in habitat perforation is not enough to change structure in bird assemblages.
• A lack of changes is also evident at guild (edge vs. forest species) and species level.
• Further research is necessary to search a higher threshold in habitat perforation inducing a change in assemblage structure.

We studied a set of common breeding birds living in a heterogeneous oak wood mosaic of Apennines (central Italy) where a wind farm occurred. Aim to assess differences in composition and structure between a treatment area (with wind farm turbines) and a control area (without wind farm turbines). We did not observe differences at assemblage (uni-and bi-variate metrics of diversity: mean species richness, Shannon–Wiener diversity index, evenness, Whittaker βwβw index and diversity/dominance diagrams), guild and species level (relative frequencies). The limited habitat perforation and dissection induced by wind farm turbines and service roads (10% in area) and the consequent changes in spatial heterogeneity and level of anthropogenic disturbance (induced by a higher motor-car and people frequentation) did not seem to affect the breeding bird communities in oak mosaics, as supported also by the diversity/dominance analysis. However, our preliminary conclusions are limited only to the indirect impact on common breeding bird species and are not related on to possible direct impacts deriving from wind farm facilities and related infrastructures (e.g., direct impact for collision). Moreover, further research is necessary to detect possible higher thresholds in habitat perforation that may induce changes in breeding bird assemblages.