The scent world of cats: where to place a urine scent mark to increase signal persistence?

Scent-marking is a predominant form of communication among felids, with urine spraying having a key role. Detectability and longevity of scent marks are recognized as crucial for efficiency of scent-marking, but there is limited research that has tested scent persistence with respect to various environmental factors. We used an experimental framework to measure human-perceived strength of felid urine smell and determine the effects of substrate, tilt and aspect of marked surfaces on persistence of the simulated scent marks. We used area under the curve (AUC), calculated for the scent strength of each scent-marked surface over time, as a proxy for urine scent preservation. Thereafter, we used ANOVA, followed by analysis of differences of interest between the marking sites, to assess the effect of environmental factors on human-perceived scent mark persistence. Odour persisted significantly better on rough surfaces, surfaces covered with moss and on surfaces with overhanging tilts, while there was no significant difference between the northerly- and southerly-oriented surfaces. The results are generally in accordance with the use and selection of marking sites previously reported for wild felids throughout the world, confirming that in their marking behaviour felids strive to prolong the persistence of scent marks. This knowledge will help researchers in interpretation of data on scent-marking and to evaluate the adaptive significance of this behaviour.