The research by MRI PAS, in collaboration with the Leibniz Institute for Zoo and Wildlife Research, Berlin, on stress levels in cervids, has shown that in red deer and roe deer populations under heavy predation pressure from wolves and lynx, stress levels are lowest and most stable compared to populations where no large predators occur and human activity dominates. This is best illustrated by the latest comic book by Tomasz Samojlik, and the inquirer may look at the original work at this address.

https://academic.oup.com/beheco/advance-article/doi/10.1093/beheco/arx142/4636144