Bridging Continents: The Expansion and Establishment of the House Bunting (Emberiza sahari) from North Africa to Europe

Range expansions driven by climate change are increasingly documented, particularly in birds. The House Bunting, a species native to North Africa, has recently established the first confirmed breeding population in mainland Europe, in Algeciras, southern Spain. This study presents the results of the first systematic census of this population, conducted in December 2024. Using a standardized survey method across a grid of hexagonal sampling units, we recorded a minimum of 18 individuals, including juveniles, indicating both successful reproduction and possible new arrivals. Observations were concentrated in low-rise urban areas, mirroring the species’ preferred habitats in Morocco. The presence of individuals with juvenile plumage in December suggests an extended breeding season, which may facilitate population growth. Given the geographical proximity to North Africa and predicted increases in aridity due to climate change, further expansion into Iberia appears likely. Although no immediate ecological impacts have been detected, potential interactions with resident species warrant continued monitoring. This study provides a baseline for assessing the establishment and growth of this population, contributing to a broader understanding of how climate change influences species distributions and the colonization dynamics of expanding bird populations.