Potential distribution of alien parakeets in Tuscany (Central Italy): a bioclimatic model approach

Abstract

Psittaciformes play a predominant role among the exotic species deliberately imported by humans all over the world, being the most popular bird pets. When released, they often establish naturalized populations, as they present a wide ecological plasticity and synanthropy. As for Tuscany, eight species have been reported (42.11% of those reported for the whole Italy), often near urban centers. Among those, two are possibly established and expanding: the rose-ringed parakeet (Psittacula krameri) and the monk parakeet (Myiopsitta monachus). This work aims to statistically reconstruct the actual extent of occurrence (EOO) of these two species through a fixed kernel method and their potential distribution through a bioclimatic envelope (BIOCLIM), using variables selected from the WORLDCLIM database, selected according to the ecological requirements of these species. BIOCLIM analysis suggests a possible expansion risk for monk parakeet and rose-ringed parakeet in Tuscany, as both species are presented with a huge amount of suitable but not occupied habitat. In particular, rose-ringed parakeet may colonize the inner part of the region, while the southern part of the region may be exposed to a possible range expansion of monk parakeet.