Doi: https://doi.org/10.13157/arla.72.2.2025.ra4
Authors: Mariano PARACUELLOS, José M. DÍAZ, José A. OÑA, Juan F. PARRILLA, Gabriel SALAS and Juan C. NEVADO
E-mail: mparacuellos@gmail.com
Published: Volume 72.2, July 2025. Pages 223-240.
Language: English
Keywords: 50 years, local and global changes, loss, migratory birds, pre-Saharan, Punta Entinas-Sabinar, resident and trans-Saharan
Summary:
The southeast of the Iberian Peninsula constitutes a strategic flyway for birds between Africa and Europe. Interest in evaluating passerine migration by means of ringing at sites within this geographical area, such as Punta Entinas-Sabinar (Almería, Spain), dates back to the 1970s. The present study analyses the long-term variations in passerine bird catches during migration from four ringing campaigns in Punta Entinas-Sabinar in the spring and autumn. We compared data from 2022- 2024 with similar studies from 1972, 1973, and 1985, conducted using the same methodology. No noticeable temporal changes were found in the specific identity and overall composition of the passerine migrant captures over the last half century. Instead, statistically significant declines were observed over the same period in the numbers of 16 of the 19 target species studied, with long-distance trans-Saharan migrants being most affected. The losses involved 70-90% of ringed passerine numbers in 50 years. No statistical relationships were found between the variations calculated for Punta Entinas-Sabinar and those on a European scale, since the impoverishment in bird abundance observed on a local scale was usually higher than that found at a larger spatial scale. Several global and local factors, such as the human disturbance in other regions of Europe and Africa, the effects of climate change and the transformation of the periphery of Punta Entinas-Sabinar by greenhouses are discussed as possible causes of the decline in bird numbers in the study area over time. The lack of correlations between local- and European-scale temporal changes would highlight the importance of the deleterious effects of local changes in land use, apart from global ones, as substantial drivers of bird declines. The present study, one of the few to analyse half a century of changes in passerine ringing captures, supports the need for more intensive long-term systematic monitoring to ascertain the historical variations of the populations of these birds in the current scenario of change.
