Is the European stonechat (Saxicola rubicola) a fully resident species in Italy? Observations on its phenology along the altitudinal gradient in central Italy

Here, I present the results of detailed field observations on two distinct populations of European stonechat Saxicola rubicola in central Italy, which challenge the view that stonechats are entirely resident in Italy. My findings exclude weather-induced altitudinal movements and strongly suggest that a portion of the Italian stonechat population exhibits obligate full or partial migration, even if wintering within Italy’s borders. In central Italy, the resident-to-migrant ratio decreases from 100 at sea level to 0 in high mountain areas at 1600 m asl, with intermediate values in the hills and low mountains. To avoid potential misinterpretations, it is important to distinguish between geographical residency and residency as an intrinsic phenological trait of birds.