Whereas most studies on overmarking in mammals analysed the rate of overmarking, that those investigate time between exploration of an olfactory stimulus and the response to it remain less common, with inconsistent results. We examined the latency in time between elimination by the sender and sniffing by the receiver, and from sniffing and overmarking, in four captive African equid species to explore differences among species, and among age and sex classes. We investigated these latency time periods in light of three potential hypotheses explaining overmarking behaviour in equids: social bonds, group cohesion, and intrasexual competition. Analysing 1684 events of sniffing and 719 of overmarking among 130 individuals, we found that (i) the time from elimination to overmarking was shorter among female friends and in parent-offspring dyads, proving support to the social bond hypothesis; (ii) intraspecific differences in time periods do not reflect the social organisation of species, thus not supporting the group cohesion hypothesis; (iii) males were more attracted to elimination of conspecifics than females, and female's eliminations were inspected longer, in line with the sexual competition hypothesis and/or reproductive behaviour. In addition, we found that the younger foals came to sniff eliminations faster than older ones, and in larger groups foals devoted longer time to sniffing the elimination before overmarking. We concluded that examination of the elimination could be driven by motivations other than the decision to overmark. Whereas overmarking serves to express bonds to a familiar individual, the latency of overmarking reflects more reproductive interests.

Departement of Biology and Ecology Faculty of Science University of Ostrava Chittussiho 10 71000 Ostrava Czech Republic

Department of Ethology Institute of Animal Science Přátelství 815 Uhříněves 10400 Prague Czech Republic

Department of Zoology Faculty of Science University of South Bohemia Branišovská 1760 37005 České Budějovice Czech Republic

Natural Resource Ecology Laboratory Warner College of Natural Resources Colorado State University Campus Delivery 1499 Fort Collins USA

Ostrava Zoo Michálkovická 2081 197 71000 Ostrava Czech Republic

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