Do red squirrels and dormice get along?

Göttingen researchers show mixed woodland boosts wildlife diversity in European forests

 

Can animals share the same space peacefully high above the ground in the treetops? A research team at the University of Göttingen has found that forests combining both deciduous and conifer trees make it easier for red squirrels and dormice to coexist. Using cameras placed high in the canopy, scientists discovered that red squirrels tend to prefer coniferous forests, while dormice are more commonly found in beech forests. However, in mixed forests that include both tree types, both species were observed living side by side. This suggests that mixed forests could play an important role in supporting biodiversity. The findings were published in the European Journal of Wildlife Research.

The study took place in northern Germany and used 80 cameras placed between 2 and 30 meters above the ground in the trees.  The researchers, with the help of professional climbers, had to climb up each tree to install, inspect and retrieve the cameras in the forest canopy. Cameras automatically recorded animals, being activated by movement and heat when animals passed through their field of view. During seven months of observation in 20 different forests, the researchers recorded 468 sightings of red squirrels and 446 of dormice. Among the dormice sightings were 249 edible dormice and 197 hazel dormice. These observations allowed the team to analyze how the presence of each species was linked to the number of beech trees and the presence of other tree-dwelling mammal species.

"Our results show that dormice and red squirrels are not avoiding each other. In fact, they can live together quite well in mixed forests," says lead author Pedro Mittelman, a PhD researcher in Wildlife Sciences at the University of Göttingen. "This is great news - it shows that forestry management systems combining tree species can benefit wildlife." The research team highlights the value of cultivating a mixture of trees as a way to support biodiversity, even in areas managed for timber production.

This study is part of the graduate programme EnriCo ("Enrichment of European beech forests with conifers: impacts of functional traits on ecosystem functioning") at the University of Göttingen. It is funded by the German Research Foundation (DFG) and contributes to ongoing efforts to better understand the functioning of pure and mixed forest ecosystems.

Original publication: Mittelman P, Pineda M, Balkenhol N (2025): Mixed broadleaf-conifer forests promote coexistence of red squirrels and doormice. European Journal of Wildlife Research, 71:67. DOI: 10.1007/s10344-025-01947-y