Wintering areas on the move in the face of warmer winters

Abstract

For several decades, there have been changes in the distance of bird migration. The Eurasian Reed Warbler Acrocephalus scirpaceus is a Trans-Saharan migratory species, which, as recent records suggest, is increasingly wintering in the Iberian Peninsula. This study investigated the strength of the influence of climate on the wintering of this insectivorous species in the Iberian Peninsula, and also used geospatial modelling to identify the most favourable areas. The model was constructed to identify the most relevant explanatory factors of this distribution and it was assessed by applying calibration and discrimination criteria, and the influence of each factor was analysed using variation partitioning. The minimum winter temperature is the most relevant factor affecting sites suitable for the wintering of this species in Europe.