Using bioacoustics to assess the presence and species richness of owls and woodpeckers in two differently managed Alpine forests

Woodpeckers and owls are considered important forest naturalness indicators and their presence reflects those of numerous other forest-dwelling species. Because of their habits and behaviour, they are often difficult to detect, and therefore the implementation of the bioacoustics discipline is suited to the survey of such taxa. In the present study we collected data about the presence and species richness of owls and woodpeckers in relation to the main forest structure and composition variables (basal area, dominant height, tree species diversity, living trees’ vegetational conditions, canopy closure percentage, total deadwood volume, decomposition stage) in two forest sites which share similar ecological characteristics, but differ in terms of management: Cajada (non-intensively managed) and Tovanella (abandoned). Both Cajada and Tovanella forests report the presence of bird species belonging to the taxa of woodpeckers and owls. The main explanatory factors for the higher number of contacts of woodpecker and owls in Cajada rather than in Tovanella are the decomposition stage of deadwood and the level of canopy closure. Management practices in Tovanella have been only recently abandoned we think that our results might change in the future. Therefore, further research is needed, also to better assess how sustainable forest management might conserve key forest feature which are crucial for the thriving of most demanding owls and woodpeckers.