Lynx effect: Predator scent reduces deer browsing on young trees

A study in south-eastern Germany found that applying lynx and wolf scents to sapling plots reduced deer visits and browsing, with lynx scent showing the strongest effect.

Researchers tested whether predator odours could protect young trees from deer in a study in south-eastern Germany. They applied lynx and wolf urine and scat, plus cow scent and water as controls, to sapling plots at 11 locations in forests where lynx and wolves have been reintroduced. Using camera traps, the team recorded red and roe deer behaviour and monitored browsing damage to planted saplings. The study was published in the Journal of Applied Ecology. Key findings: - The experiment compared lynx and wolf scent, cow scent, and water control across 11 sapling plots in south-eastern Germany. - Deer visited less and spent less time browsing in plots treated with predator scents, particularly lynx scent, which led to reduced damage to saplings. - Camera traps recorded red and roe deer responses, and researchers monitored sapling browsing to measure effects. - Deer showed a stronger response to lynx scent than to wolf scent; researchers noted lynx are ambush predators and wolves were still establishing locally. - The researchers reported that the presence of carnivores, or even just their scent, could help reduce browsing pressure from overabundant deer and support forest recovery. - The article notes discussions about possible lynx reintroduction in parts of Britain, where researchers expect similar but probably weaker effects and where some people have expressed concerns about livestock impacts. Summary: The experiment indicates that predator odours, especially from lynx, reduced deer activity and browsing on saplings in the studied forest, which could lessen damage to regenerating woods. Researchers said these scent effects reflect an innate fear response and that effects would likely be weaker in regions long without these predators. Rewilding discussions, including potential lynx reintroductions in parts of Britain, are ongoing, and wider ecological outcomes are undetermined at this time.