Scent marking is a fundamental component of carnivore communication and can mediate spatial interactions among sympatric species. In this study, we investigated olfactory marking behaviour and interspecific interactions between Pallas's cat (Otocolobus manul) and red fox (Vulpes vulpes) in the central Mongolian steppe. We aimed to assess whether Pallas's cat exhibits spatial or temporal responses to red fox scent marks. We analyzed data from a continuous camera-trapping survey conducted between August 2020 and August 2024 across 57 sites, totaling 32,722 trap-days. Independent detection events involving olfactory behaviors were classified into scent-producing and scent-investigative categories. Spatial associations of the marking sites for both species were evaluated using contingency analyses, while temporal responses were assessed by comparing the time intervals between successive marking events. Pallas's cat and red fox were recorded in 267 and 798 independent detection events, respectively, with marking activity detected at 45 of the 57 camera-trap sites. Pallas's cat exhibited six types of olfactory behaviors, whereas red fox exhibited five, with olfactory investigation being the most frequent behavior in both species. Spatial analyses revealed a strong negative association between Pallas's cat and red fox marking sites, indicating marked spatial segregation consistent with avoidance by Pallas's cat. In contrast, no significant difference was detected in the temporal intervals between Pallas's cat markings following red fox activity and intervals between consecutive conspecific markings. These findings demonstrate that Pallas's cat responds to red fox presence primarily through spatial avoidance rather than temporal adjustment of marking behavior. This pattern suggests asymmetric interspecific interactions, potentially reflecting avoidance by Pallas's cat in response to red fox presence, highlighting the role of spatial mechanisms in structuring carnivore coexistence in open steppe ecosystems.
Marking sites, Mesocarnivore guild, Olfactory communication, Otocolobus manaul, Spatial avoidance, Vulpes vulpes
