Ecology Bark beetles wrongly have a bad reputation
Bad for trees, but good for woodpeckers: a new study shows that a bark beetle infestation increases the number of woodpeckers. Even years after a forest was infested by the pest, the woodpecker population remained high.
05.11.2025, 08:01
SDA
Bark beetles wrongly have a bad reputation, wrote the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) in a press release on the study on Wednesday.
For the study, which was published in the "Journal of Animal Ecology", WSL researchers compiled three decades of data on bark beetle infestations and woodpecker populations. The researchers used computer models to look for correlations in this data.
The result: after a bark beetle infestation, the number of woodpeckers increased significantly. Of the three woodpecker species studied, the researchers found the strongest correlations with the three-toed woodpecker.
The scientists expected this, as this woodpecker eats the bark beetles. But even after infested trees had been removed, woodpecker numbers remained high.
According to the researchers, this shows that the birds benefit from the dead wood that the beetles leave behind by damaging the trees in large quantities.
Forestry has already recognized the importance of deadwood for biodiversity and is specifically promoting it, the WSL noted. These efforts are having an effect and there is now more deadwood in Swiss forests than just a few years ago.
