Birds as indicators of recent environmental changes in the apennines (foreste casentinesi national park, central italy)

Abstract

Starting from a data-set of 175 point counts (5 min duration) repeated twice a year from 1992 to 2002 in the Foreste Casentinesi National Park (Apennines, central Italy), the trends of species and of some selected ecological and phenological guilds were analysed. Among the 61 testable species, a significant increase (linear or quadratic regressions) involved 15 species, whereas 8 decreased. No significant trend was found for the remaining 38 species. The bark feeders guild, as well as tree-cavity nesters and ground feeders showed an increase, whereas foliage feeders and ground nesters showed no significant changes. Short-distance migrants and residents showed an increase, whereas long-distance migrants showed no change. The overall picture obtained from these data fits well the habitat changes occurring in the study area: i) ageing of woods (with a remarkable increase in the proportion of mature stands in the study period); ii) afforestation of pastures and farmland, a long-term process that started at least 150 years ago. These processes are widespread in the Mediterranean mountains, and it is therefore possible that the situation in the Foreste Casentinesi could have some general meaning, though the lack of regional bird monitoring programs impedes reliable comparisons. © 2004 Taylor & Francis Group, LLC.