Not only pond sliders: freshwater turtles in the water bodies of the Milan northern urban area (Italy)

Abstract

Freshwater turtles represent one of the most common pets released in urban water bodies. In Europe, after the ban on the import of Trachemys scripta, other non-native turtle species now dominate the legal pet trade. Some of these species have high invasive potential, such as the well-known slider turtle, but their diffusion outside their native range is poorly known. This work summarises presence data about non-native freshwater turtles, different from slider turtles T. scripta, into two urban parks located at the northern boundary of the Milan outskirts (Italy, Lombardy). Turtle detections were obtained merging field surveys conducted from 2014 to 2020, with sparse pictures taken by occasional observers. The situation depicted shows, in addition to the ubiquitous spread of slider turtle subspecies and hybrids in both parks, the frequent presence of other multiple genera such as Pseudemys and Graptemys. Isolated individuals of Apalone spinifera, Graptemys ouachitensis, Mauremys sinensis, Pelomedusa subrufa and Sternotherus carinatus were also found. I also detected one Emys orbicularis, probably escaped or released.