Distribución y abundancia de la población reproductora de Treparriscos ( Tichodroma muraria ) en Aragón

With the completion of the Ornithological Atlas of Aragon only a first approximation of the distribution of the breeding population of Wallcreeper (Tichodroma muraria) in Aragon was made. In this paper we update the information about its distribution and we made a first estimate of population size. Overall total 145 records were obtained during the breeding season (May-August) between the years 1982 to 2014 are obtained. Breeding areas were located at an average altitude of 2.409 ± 572 meters, and 62% records were made in areas with basic rocks. Nest building took place between May and early June, incubation between June and July, chicks rearing between June and late July and family groups were formed in August. The distribution encompasses 40 UTM 10x10 km (an increase of 133% on the distribution given in the Ornithological Atlas of Aragon) and 87 1x1 Km squares. It is present in all the Aragon Pyrenees mountain ranges, except for Culfreda and Acherito and Mesa de los Tres Reyes, where no records of presence were obtained. The area of occupancy with proven presence was 83 km2 and potential occupancy areas was 664.96 km2 and an area of maximum occupancy of 495.45 km2. We estimated population size on 705 breeding territories potential for the area, territories with a density of 0.13 territories/km2 and 525 territories for the area of maximum occupancy, with a density of 0.18 territories/km2 Taking into account existing information available on the species in Aragon (1,410 breeding individuals), the Wallcreeper should be included in the category of Least Concern according (IUCN criteria) and its population size should be updated in the Pyrenees (southern slope).