Don’t spit in the soup: faecal avoidance in foraging wild Alpine ibex, Capra ibex

Faeces are a major vehicle for transmission of parasites among ungulate hosts. Avoiding feeding in proximity to faeces has been shown to be an antiparasitic strategy in experimental settings with domestic and semidomestic ungulates. However, few studies have tested the faecal avoidance hypothesis in wild herbivores. We tested the faecal avoidance hypothesis in a wild population of Alpine ibex by comparing the quantity of faeces in grazed and avoided areas. We counted faecal pellets within a plot around a grazing individual and a plot around a spot actively avoided by the same individual. As predicted, grazed plots had lower densities of faecal pellets than avoided plots. Fresh faeces were avoided more often than medium-aged and old faeces. We found consistent differences in the level of faecal avoidance among individuals, but this was not related to the level of gastrointestinal parasite infection or to the age of the host. Our results suggest that wild Alpine ibex actively avoid foraging near faeces but the antiparasitic value of this behaviour is not evident.