Synchrony, scale and temporal dynamics of Rock partridge (Alectoris graeca saxatilis) populations in the Dolomites

1. We examine harvesting records of rock partridge (Alectoris graeca saxatilis) to first identify thepresence of cycles in a species with a southern European distribution and then examine synchronybetween populations at a range of scales.2. Hunting records from 1965 to 1994 were obtained from 210 hunting areas and analysed at threespatial scales: sub-population, population and metapopulation scale. Rock partridge exhibited cyclicfluctuations in about 40% of the time series with a period of 4-7 years. The results did not changewith spatial scale. The density dependent structure of the populations showed that most populationsexhibited damped oscillations.3. The proportion of populations that were in synchrony increased with scale from the population tometapopulation level. There was no decline in synchrony with distance but a large variation betweenpopulations irrespective of distance.4. The populations clustered into dry and wet habitats, with those in the dry habitat being more cyclic.We suggest the lack of spatial synchrony with distance but greater synchrony within habitats mayreflect the influence of stochastic events operating on populations with different density dependencestructures.

Isabella M. Cattadori, Peter J. Hudson Stefano Merler & Annapaola Rizzoli, geen referentie