The lynx effect: how the smell of predators could help forest restoration

The lynx effect: how the smell of predators could help forest restoration - British Ecological Society

Just the smell of predators, like lynx, is enough to reduce deer browsing, finds new research.

A roe deer stands in a snowy woodland. — Roe deer were one of the species the researchers monitored in the study. Credit Walter Di Nicola.

New research finds that the mere smell of predators, like lynx, is enough to make deer more cautious and spend less time browsing on tree saplings, offering a potential tool for forest recovery.

In a field experiment conducted in the forests of south-eastern Germany, researchers from the University of Freiburg added lynx and wolf urine and scat to plots of tree saplings and then monitored how wild deer responded.

They found that plots with the scent of predators, particularly lynx, had less browsing damage to young trees than control plots, and that deer visited predator-scented plots less and spent less time foraging when they were there.

Overbrowsing by deer is a major threat to forest regeneration, damaging biodiversity and causing economic losses for the forestry sector. Mitigating browsing damage usually involves substantial human effort and financial resources.

Walter Di Nicola, one of the lead researchers, said: “At a time when debates around large carnivore conservation often focus on conflicts, our study highlights the benefits these species bring to landscapes. The presence of carnivores, even just their scent, could help reduce the ecological and economic problems associated with browsing from overabundant deer populations.”

The research, published in Journal of Applied Ecology, was conducted in forests where both lynx and wolves have been reintroduced. But the researchers say they would expect similar effects in countries like the UK where these predators have long been absent.

Walter said: “In the UK we would expect similar but probably weaker effects. Deer still have some innate fear of predators, even if those predators have been absent for generations. Where predators return, we expect these responses – and their ecological benefits – to become stronger over time.”