Research overview: prey-selectivity indices in felid diet studies

A methodological survey of the indices used to measure whether felids prefer or avoid prey relative to availability, including the Jacobs index, Ivlev's electivity and related measures central to the prey-preference literature. The overview explains how kill or scat frequencies are weighted by independent estimates of prey abundance to derive selectivity, the statistical pitfalls of compositional data, and how preferred prey-weight ranges are calculated. It discusses why selectivity, not raw diet composition, reveals genuine preference, and how indices are compared across species to quantify dietary overlap. These tools underpin the Hayward prey-preference series and most quantitative felid diet work, and the survey highlights ongoing debates about availability estimation and the interpretation of selectivity values.