Research overview: defining core areas and isopleth selection

Home ranges are often summarized by isopleths, contours of the utilization distribution enclosing a chosen percentage of use, with the full range commonly set at 95 percent and the core at 50 percent. This overview examines how those thresholds are chosen and the more defensible alternative of identifying core areas empirically, for example where observed use exceeds that expected under uniform space use. Core areas often correspond to denning sites, prey concentrations, or defended territory centers, making their delineation biologically meaningful for cats. The overview cautions that arbitrary percentage cutoffs can mislead and that core-area definition should reflect the animal's actual intensity of use. Properly bounding cores matters for conservation planning, conflict mapping, and comparisons of how intensively felids exploit their ranges.