Urban Foraging and Plant Toxicological Risks for Rose-Ringed Parakeets (Psittacula krameri) in Athens

Abstract

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. 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 density remained relatively stable, peaking in autumn. Toxicity assessment of aqueous plant extracts with Brine Shrimp (Artemia franciscana) Lethality Test (BSLT) identified chinaberries as the most toxic, indicating potential dietary risks. These findings indicate that P. krameri exhibits flexible, opportunistic foraging and can tolerate plant compounds that are harmful to other vertebrates, suggesting that toxicity does not seem to limit its diet. 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.