DENSITY AND HABITAT REQUIREMENTS OF SYMPATRIC HARES AND COTTONTAILS

(Lepus europaeus) and Eastern cottontail (Sylvilagus floridanus) were assessed during feed-ing activity in an intensively cultivated area in northern Italy. Hare average density (74 ind./km2) was comparable to the highest values reported for European farming areas. Pre-and post-breeding density fluctuated widely across the study years, probably as a conse-quence of changes in the carrying capacity of the study area. Cottontail population size pro-gressively increased, as expected for a recently introduced species supported by high repro-ductive performances. Hares used both crops and spontaneous vegetation during their feed-ing activity. Conversely, cottontails avoided winter cereals and preferred to feed on alfalfa. Our results suggest that simplified agro-ecosystems cannot maintain high density hare pop-ulations even at a short time scale. Landscape heterogeneity could enhance the chances of coexistence between the two lagomorphs