Tamaño de población y parámetros reproductores del halcón peregrino "Falco peregrinus" en Álava (País Vasco, España). Año 2016

In 2016, a census was carried out of the population of Peregrine Falcon Falco peregrinus in the province of Alava, maintaining the the periodicity of ten years between consecutive surveys applied on previous occasions. With a standardized methodology which estab- lished the number of visits to each territory and their duration, 31 territorial pairs were detected. This figure indicates a remarkable population stability over the last two decades. The territories with a more continuous occupancy pattern during this period were those corresponding to cliffs with a commanding position over the surrounding terrain. A pro- ductivity of 1.40 fledged young/ territorial pair was obtained in 2016, a remarkable recov- ery from the low breeding success observed ten years earlier. The most concerning aspect of the present census was the substantial proportion of immature females forming part of a pair (17%), which may be a sign of high adult mortality.