Hazel dormouse

The hazel dormouse (Muscardinus avellanarius) is a small rodent belonging to the Gliridae family. While protected in many regions as a species of conservation concern, in specific agricultural settings, it can act as a pest, causing economic damage to hazelnut orchards and commercial fruit nurseries by consuming valuable plant parts.

The biology of the dormouse is characterized by a seasonal cycle that includes a hibernation period. During their active phase, they are nocturnal and arboreal, spending most of their time in the canopy. Their reliance on high-energy foods makes orchards with hazelnut or fruit trees particularly attractive, especially during the pre-hibernation fattening phase.

Damage caused by this rodent typically involves the consumption of tree buds, bark, and ripening nuts. In hazelnut plantations, they are known for gnawing precise, smooth-edged holes into the nut shells to access the kernel. This damage is often mistaken for that of other rodents, but the specific bite marks are a key diagnostic feature for experienced agronomists.

The presence of Muscardinus avellanarius can be confirmed by spotting their distinctive, spherical nests made of woven leaves and grass tucked into thicket branches. In orchards, excessive gnawing on bark can lead to branch desiccation and structural weakness of young saplings, reducing overall plant vigor.

Managing the impact of the hazel dormouse requires non-lethal and preventative strategies to maintain both ecological balance and crop safety:

• Installing tree guards or metal collars to prevent climbing access to fruiting trees.
• Maintaining clean orchards by removing dense, neglected undergrowth that facilitates nesting.
• Employing sonic or scent-based deterrents during the critical stages of nut ripening.
• Strategic pruning to increase canopy visibility and reduce the density of sheltered nesting spots.