The red-billed leiothrix (Leiothrix lutea): a new invasive species for Britain?

Invasive non-native species (INNS) are one of the major threats to global biodiversity. Climate change and garden bird-feeding may facilitate the establishment of INNS. The Red-billed Leiothrix Leiothrix lutea is a small woodland passerine, native to subtropical Asia, that is an INNS in several parts of the world, including Europe, following escapes from the aviculture trade. Recently, populations of Red-billed Leiothrix have established in Spain, Portugal, Italy and France. Previous studies have shown that much of Europe is suitable for the species, including southern Britain. The Red-billed Leiothrix has not previously been considered as at high risk of establishment in Britain, but we document recent records, including a cluster in southern England, suggesting that establishment may already be underway. We discuss the potential negative impacts of this invasive species on local ecosystems, and how a warming climate and garden bird-feeding might assist their establishment in temperate Europe. We also highlight the importance of improved recording to monitor the potential establishment of INNS, such as the Red-billed Leiothrix, in Britain.