Modelling the distribution of an introduced species: The coypu Myocastor coypus (Mammalia, Rodentia) in Piedmont region, NW Italy

Model-based analyses of species-habitat relationships can help to clarify which factors influence the establishment and spread of species. The coypu (Myocastor coypus) is a semi-aquatic rodent native to South America, which has been introduced worldwide, including Italy. We used logistic regression to analyse the species distribution according to habitat attributes of agro-ecosystems in Piedmont Region. The resulting model correctly predicted the presence and absence of the coypu in the initial data and also in the part of the study area used for cross-validation. Our analysis confirmed that the coypu is a typical lowland species, which particularly uses flat areas below 300 m a.s.l. The presence of coypus was strongly correlated with the presence of rice fields. During the rice-growing season, a network of canals with running water enables them to colonize this vast area. On the other hand, coypus are less likely to be present where the surface covered by woodlands and urban areas, other crops patches density, and orchards and poplar plantations patch sizes increase. A global coypu control strategy must be based primarily on preventing further introductions, and the results of this study could help to produce future risk assessments.