Red-legged partridge monitoring and population trends

Thanks to the Pan-European Common Birds Monitoring Scheme and Breeding Bird Survey, the temporal changes in abundance of the Red-legged Partridge are known in most countries of its area of distribution. However, these are based on abundance indices and no strong inference is possible about potential causes of local trends. Robust estimates of abundance or densities at national scale are still lacking. Information from hunting bags cannot be used owing to the inclusion of released Red-legged Partridges in those numbers. Even in the absence of released individuals in hunting bags, these estimates cannot be used owing to a lack of knowledge of variations in reporting behaviour in Europe and potential age-specific mortality. Numbers at the local scale are obtained using similar (although not equal) methods across countries based on line/point transect methods. Given that some capture-recapture studies have been carried out from time to time in most of the distribution range, their results could help to estimate the demographic parameters required for management. Finally, given that these common methods are applied with, possibly, some avoidable differences, a more integrative strategy of methodological design and spatial sampling may make it possible to extrapolate estimates from regional to national/continental scale, and to provide assessments of abundance as well as spatial and temporal variation in Red-legged Partridge population size. This global approach may increase the current value of monitoring to all stakeholders interested in Red-legged Partridges.