Alien shades of grey: new occurrences and relevant spread of Sciurus carolinensis in Italy

Abstract

The eastern grey squirrel is listed among the worst invasive species throughout the world. This species of American origin is currently replacing the native Eurasian red squirrel in most of the Great Britain, as well as in parts of Ireland and Italy. It may debark trees and exert damages to woodlands and tree plantations. Therefore, its spread may be deleterious for biodiversity and environment, emphasising the need for a rapid detection in new areas of occurrence. In this work, we reported for the first time, the presence of new populations of this invasive species in Tuscany (Central Italy) and some updates and analyses regarding the status of this species in Veneto (North-Eastern Italy). Occurrences were collected through citizen-science contributory approach supported by photos, road-kills, and/or hair-tube sampling. Field investigations ad hoc were carried out in Veneto and Tuscany to confirm the repeated reports in the surroundings of Arezzo and in the province of Siena