Patterns of activity rhythms of invasive coypus Myocastor coypus inferred through camera-trapping

Studies on activity rhythms are pivotal for the management of invasive alien species, as they provide basic insights into species basic ecology and may increase the success of control programs. The coypu Myocastor coypus, introduced from South America for fur farms, has become one of the most invasive rodents in Europe. Introduced coypus may affect crop productions, as well as natural vegetation and the breeding success of wading birds. In this study, we examined activity data collected through intensive camera-trapping in three Italian areas, including two natural areas in Northern and Central Italy, and a suburban area in Central Italy. Coypus were mostly diurnal in areas characterised by low predator pressure and, at night, they are mostly active in bright moonlight. Conversely, where predators, human pressure or numerical control programmes are present, coypus remarkably shift their behaviour towards crepuscular and night hours. In these last areas, nocturnal activity increased as moonlight decreased, possibly to reduce predation risk or encounters with humans. Where winter temperature are low, diurnal habits may have developed as a physiological adaptation and a strategy to preserve energy, potentially achieving a cost/effective thermal balance.