Responsiveness to acoustic stimulation, distribution and habitat preferences of the Lesser Spotted Woodpecker, Dendrocopos minor, in Friuli-Venezia Giulia (North-eastern Italy)

From 2005 to 2013 in Friuli-Venezia Giulia (NE Italy), using the playback method, a study on the Lesser Spotted Woodpecker, Dendrocopos minor, was carried out. The aims were to identify the trends in distribution, the range, and the habitat preferences, along with the evaluation of the responsiveness to acoustic stimulation. The Lesser Spotted Woodpecker responded in 10.67% of the points where a conspecifics stimulus was emitted, demonstrating a “strong” responsiveness to the first stimulus. In the case of a response, males prevailed, and the Lesser Spotted Woodpecker was confirmed as the Picidae species that tended to show itself the most (79.17% of the points). Thanks to the tendency to expand the range and to occupy new zones within the known range, most of the suitable environments were occupied in the Provinces of Trieste and Gorizia and from the lowlands to the outer prealpine zone, even in urban areas. In the montane zone, expansion occurred through ascending of the valleys and slopes. The species was found from sea level to 1200 m (mean altitude: 429±270 SD m a.s.l.) and particularly below 800 m a.s.l. (about 90% of the contacts). Of all the contacts, 71.69% occurred in broadleaf woodlands. Woodlands along watercourses were revealed to be very important (most highly represented forest type with more than one fifth of contacts), which have allowed the species to live in the lowlands and subsequently colonize other suitable environments, and the countryside and orchards, which are fundamental in the mountains for the spread and permanence of the taxon. In some areas, densities of 1.11-2.50 territories/100 ha were obtained. In Friuli-Venezia Giulia, a population of 150-190 pairs has been estimated, with an increase of just over 60% compared to the beginning of the century. Finally, some aspects concerning conservation-related problems are reported.