Patterns of spatiotemporal activity of an alien lagomorph inferred through camera-trapping.
Assessing wildlife activity rhythms is crucial to design effective management programmes for invasive alien species. Among the most widespread alien mammals in Italy, the Eastern cottontail Sylvilagus floridanus has been introduced from North America for hunting purposes and it is now very common in the Northern and Central regions. In this study, we conducted a camera-trapping survey to determine seasonal patterns of activity rhythms of this small lagomorph in Northern Italy, as well as the overlap of temporal rhythms with its main mammal predators. Eastern cottontails were mostly crepuscular and nocturnal throughout the year. Inter-seasonal overlaps of activity patterns were always lower than 75%, as activity of the Eastern cottontail was linked to photoperiod. The bimodal activity, with significant peaks at dawn and dusk, may represent an adaptation of this species to limit encounters with nocturnal predators, i.e. red foxes Vulpes vulpes and stray cats Felis catus in our study area. Although activity increased during the first hours of daylight during the mating season, the temperature seems to be not correlated to cottontail activity. Cottontails responded to the increased predation risk on bright moonlight nights, when red foxes and stray cats were most active, by significantly reducing their activity in the full moon throughout the year and in every single season. Conversely, spatial overlap between cottontails and predators was high. We suggest that individual counts and direct removal methods (i.e. firearms or trapping) for this alien lagomorph should be carried out at dawn or at dusk, when the probability to spot active cottontails is the highest.