The results show that, contrary to the initial hypothesis, the human urine had no effect as a repellent against the wood mouse, a scatter-hoarder rodent whose acorn predation activity, alone or in combination with other mice species, is one of the main limiting factors for the success of oak forest restoration via direct seeding.

Under all these circumstances that simulate more realistic conditions than previous studies, the results still show no effect of human urine. I therefore suggest the conclusion that human urine is not useful to protect acorns from mice predation and that we may focus our efforts in finding alternative repellents.

Implications for Practice

Direct seeding of acorns can be an efficient method to restore oak forests, but for that, it is necessary to protect seeds against predation by rodents.

Predator scents derived from excrements, urine, or glands can elicit a fear response in rodents and act as repellents to protect acorns.

However, human urine did not provoke a fear response in the wood mouse, indicating its inefficiency in protecting acorns.

The research on animal-derived scents to deter seed predators should focus on other substances and discard human urine as a candidate.