Urban Foraging and Toxicity of Rose-Ringed Parakeets (Psittacula krameri) in Athens

The Rose-ringed Parakeet (Psittacula krameri) is an invasive parrot increasingly established in European cities, including Athens, Greece, yet its diet and exposure to plant toxins in Mediterranean ecosystems remain poorly documented. We examined seasonal foraging patterns in Athens and assessed the toxicity of key food items using a brine shrimp lethality assay. Field observations recorded 601 feeding events across 10 plant species, and eight commonly consumed foods were tested with Artemia franciscana nauplii exposed to aqueous extracts for 48 hours to determine LC50 values and toxicity classes. Four foods—cypress seeds (Cupressus sempervirens), chinaberries (Melia azedarach), Canary Island dates (Phoenix canariensis), and olives (Olea europaea)—accounted for 82.9% of feeding events. Dietary diversity was highest in winter and summer, while foraging presence remained relatively stable, peaking in autumn. Toxicity assays identified chinaberries as most toxic and cypress seeds as least, indicating potential dietary risks. These findings show that P. krameri exhibits flexible, opportunistic foraging and tolerates plant compounds harmful to other vertebrates. Seasonal dietary shifts and ecological plasticity likely support its urban invasion success, highlighting the importance of understanding diet composition and potential exposure to plant toxins in urban parakeet populations.