Do wild ungulates experience higher stress with humans than with large carnivores?

Predation is a major selective pressure for prey; however, the stress response to predation risk and the relative importance of natural versus anthropogenic stress factors in wild populations of animals have rarely been studied. We investigated the level of fecal glucocorticoid metabolites (FGMs) in 6 populations of red deer and roe deer exposed to potentially different levels of stress, resulting from both natural (predator presence, forest cover, undergrowth, ungulate density, and temperature) and anthropogenic (hunting harvest, percentage of build-up areas, and road density) factors. We found the highest and most variable FGM concentrations in both ungulates in areas without large carnivores, and the lowest and least variable FGM levels in areas with wolf and lynx. Anthropogenic factors (hunting harvest, roads, and built-up area) positively correlated with the gradient of FGM levels in both species. Both the mean and the variance of the FGM concentrations measured within populations ...