Rose-Ringed Parakeets (Psittacula krameri, Scopoli, 1769) in Turkey: Is the Threat Rising in the Future

Abstract

Biological invasions are one of the major threats to biodiversity and ecosystem functioning worldwide. Rose-ringed Parakeets (Psittacula krameri) are well-known invaders and have established populations in over 40 countries outside their native range. Regular records of Rose-ringed Parakeets in Turkey go back to 1975, and the species has established populations in at least ten cities, including in metropolitan areas such as Istanbul, Izmir, and Ankara. To understand the scale of the invasion potential of Rose-ringed Parakeets in Turkey, first, we estimated their current local population size through roost counts carried out in 2020 and 2021 in four cities. Then, we used ecological niche modeling to forecast the present-time and future climatic habitat suitability over three different periods (2041-2060; 2061-2080; 2081-2100). Field surveys and citizen science data revealed the presence of the species in 37 provinces in Turkey. Our counts indicated a rapid population growth from 1355 individuals in 2015 to 6000 individuals in 2021. The ecological niche modeling predicted an overall 50% reduction in species' potential habitats in Turkey by 2100 due to climate change. Suitable habitats in Central Anatolia are predicted to shrink by the model, while those in Thrace and the coastal areas of Turkey will remain stable. Even though model results indicate a future reduction in suitable habitats for Rose-ringed Parakeets in Turkey, we argue the need for long-term management, particularly in coastal cities where already-established populations are increasing in size.