Changes in abundance and the risk of extinction of the rock partridge Alectoris graeca saxatilis in the Dolomitic Alps were investigated using a density-dependent model that incorporated dispersal and environmental stochasticity. The study was based on spring and summer counts collected from sample areas in geographically distinct mountain groups. Extinction probability was investigated by simulating a discrete population and a metapopulation consisting of local populations connected by dispersal. Persistence was not guaranteed when the species was examined as a discrete population. When we used a metapopulation approach, the persistence was assured but local extinctions with subsequent recolonizations of a number of empty areas were observed. The analysis was repeated using hunting statistics, when there were no restrictions on hunting policies, and a similar high extinction pattern was found. Our simulations suggested that long-term persistence of rock partridge could be guaranteed only when immigration was included into the demographic model. However, if the increased population's fragmentation recorded since the 1950s persists the extinction of some of the subpopulations appears inevitable.
All Science Journal Classification (ASJC) codes
- Nature and Landscape Conservation