A new exotic bird in Europe: recent spread and potential range of Red‐billed Leiothrix Leiothrix lutea in Catalonia (northeast Iberian Peninsula)

Abstract

Capsule Following recent introduction in Spain, Red‐billed Leiothrix have the potential to attain a wide distribution in Catalonia and probably in other parts of Europe. Aim To investigate past, present and potential distribution of this exotic species in Catalonia (northeast Iberian Peninsula). Methods We collected data on the species’ occurrence over the period 1992–2008 and used information obtained in other regions where it has previously established to produce hypotheses about the ecological processes that affect its population increase and range expansion. We then generated fine‐grained distribution maps covering the entire region for the periods 1992–2001 and 2002–2008, and for the species’ potential range according to its specific habitat requirements. Results Since being first detected in the wild in the Collserola Park, near the city of Barcelona, Red‐billed Leiothrix have expanded to neighbouring forested areas. The wild population is currently in a phase of exponential growth and, according to our habitat suitability model, the species’ potential distribution in Catalonia might be 36 times greater than at present. Conclusion Our results suggest that the Red‐billed Leiothrix has the potential to attain a widespread distribution over large regions of Europe in the near future. However, we discuss several factors that might affect these predictions.