Science chats with a Spanish ecologist who tried a surprising tactic to stop mice from eating acorns.
In the mountains of southeastern Spain, a tiny wood mouse (Apodemus sylvaticus) sniffs out its dinner. The shrubs and pine trees of the Sierra Nevada give off several intriguing smells, including the nutty aroma of acorns from the Holm oak (Quercus ilex). But these particular acorns have another, more pungent odor—as though they just emerged from an ammonia bath.
As it turns out, they have—thanks to a peculiar experiment in forestry management. The project, led by University of Granada ecologist Jorge Castro, is part of a larger effort to repel mice, birds, and other forest creatures that snack on seeds planted to aid in reforestation efforts. In a study published earlier this month, Castro boldly asks: Does dousing acorns with human urine stop mice from eating them?
Alas, he reports in Restoration Ecology, the answer is a resounding—and unfortunate—no. As video recordings of the study area reveal, rodents and other animals seem undeterred by the scent of pee-covered seeds. Even so, Castro says, the work highlights the kind of outside-the-box thinking scientists may need to restore forests devastated by logging, climate change, and other human activities.