Experience increases defensive responses of White‐fronted Woodpeckers towards the invasive European Starling

Invasive species like the European Starling Sturnus vulgaris , which is rapidly expanding in South America, can threaten native birds through nest usurpation, making timely threat recognition essential for nest defence. Using model presentation experiments at 20 White‐fronted Woodpecker Melanerpes cactorum active cavities, we recorded 78 attacks of woodpeckers across 40 experimental sessions in Córdoba, Argentina, to test the hypothesis that their defensive behaviour towards this aggressive competitor is learned. Woodpeckers with previous exposure to European Starlings exhibited significantly higher aggression towards this species model, while naive individuals showed no differential response between European Starling and control models. These findings highlight the behavioural adaptability of native woodpeckers when facing novel aggressive invaders like the European Starling, but also underline their potential vulnerability during the initial stages of the invasion.