In the evolutionary biology of sexual reproduction the operational sex ratio (OSR), is the ratio of sexually competing males that are ready to mate to sexually competing females that are ready to mate,[63][64][65] or alternatively the local ratio of fertilizable females to sexually active males at any given time.[66] This is different from the physical sex ratio because it does not take into account sexually inactive or non-competitive individuals (individuals that do not compete for mates). On occasion, regions with a high male-low female sex ratio, e.g. Alaska, have shown a correlation with a higher rate of reported rape.[67]