Excreta-mediated olfactory communication in Konik stallions: A preliminary study

The aim of this preliminary study was to assess whether adult stallions differentiate their olfactory and marking behavior toward the excreta of potential rivals depending on their age, libido, hormonal status, and the season of the year. Five Konik stallions were individually exposed to own and each others' feces in a round pen during 8 observation sessions from February to November. The youngest stallion's feces were sniffed for a significantly longer period and were defecated or urinated on significantly more often, in addition to receiving more flehmen reactions. The stallion with the highest libido sniffed feces significantly longer. Alien feces were sniffed significantly longer than an individual's own feces, except for the youngest stallion. Overmarking of existing feces with urine was significantly less frequent than through defecation and was observed only outside of the reproductive season. Defecations on feces were most frequent after the peak of the reproductive season. A stallion's libido rank correlated perfectly with the number of defecations performed on alien feces (rs = 1.000). Sniffing of feces occurred for a longer time before the peak of the reproductive season, and flehmen was performed primarily on spots around feces and significantly more often in the peak of the reproductive season (May). Fecal testosterone and androstenedione concentrations were significantly higher in April and May but did not differ significantly between stallions. Testosterone concentrations were positively correlated with duration of performed sniffing feces and negatively correlated with the duration the individual's feces were sniffed. It was for the first time shown which individual social information could be mediated by defecation and sniffing feces in adult stallions.