Habitat overlap between sympatric European hares (Lepus europaeus) and Eastern cottontails (Sylvilagus floridanus) in northern Italy

摘要

In northern Italy, the range of the Eastern cottontail (Sylvilagus floridanus) largely overlaps with that of the native European hare (Lepus europaeus) on the Po Plain. Both species appear to have similar habitat requirements. We studied habitat selection by hares and cottontails during feeding activity from September 2006 to August 2007 in two areas where they occur alone (allopatry) and in one area where they occur together (sympatry). The three areas were basically similar, so that shifts in habitat use observed in sympatry should reflect the response to interspecific competition. Habitat selection was examined at micro- and macro-habitat levels throughout seasons. Habitat breadth of both species followed the change of resource availability through seasons in allopatry as well as in sympatry. No shifts in habitat use were evident at macro-habitat level, even during autumn which was the limiting season. Exploitation of shared habitats by the two species seems to be promoted by differential micro-habitat use within macro-habitat types. Cottontails used woods with dense understory in greater proportion than hares, and their present sites were concentrated within the maximum distance of 20?m of the nearest shelter site. Hares were more likely than cottontails to exploit crops, and their sites were distributed even greater than 80?m away from permanent cover patches. The habitat heterogeneity of agricultural ecosystems within the sympatry range could buffer the negative effects of external factors (climate, human disturbance and predation) on hares, and enhance the chances of exploitation of shared habitats by both species.