Temporal partitioning among native and alien lagomorphs and their predator: insights into coexistence mechanisms from long-term camera trapping

The introduction of alien species can alter existing species interactions and behaviours, posing new challenges for wildlife conservation and management. Long-term data provide an invaluable resource for testing theoretical principles and understanding species’ responses to new colonisers. In this study, we used camera-trap data to assess temporal partitioning among two lagomorphs—the native European hare (Lepus europaeus) and the alien Eastern cottontail (Sylvilagus floridanus), a rabbit species native to Northern and Central America—and their principal predator, the red fox (Vulpes vulpes), before and after the Eastern cottontail colonised the study area. Our results reveal that, in both phases, the European hare and the red fox exhibited a low degree of temporal overlap. The red fox showed predominantly nocturnal activity, whereas the hare consistently showed a strongly bimodal pattern with peaks around sunrise (or early morning) and sunset. This temporal partitioning appears to be a key mechanism by which the European hare minimises encounters with the red fox, thereby reducing predation risk. The arrival of the Eastern cottontail did not modify the hare’s diel activity patterns, while the red fox exhibited subtle shifts in its activity rhythms, possibly reflecting adaptive foraging in response to changing prey availability. The Eastern cottontail showed seasonal behavioural plasticity in its activity rhythm, being predominantly nocturnal during the cold season and shifting to a bimodal pattern with a marked peak in the early morning (one hour preceding that of the European hare) during the warm season. In the cold season, when resource scarcity may force the cottontail to occupy the same spatial locations at a fine scale, temporal overlap with the native lagomorph was lower. We suggested that temporal segregation with the European hare is a key mechanism allowing the Eastern cottontail to establish in the invaded area. These findings underscore the role of temporal behavioural plasticity in mediating interspecific interactions and facilitating the success of alien species such as the Eastern cottontail.