Atlas der Säugetiere Nordrhein-Westfalens

Haselmaus

337 entries

Hazel dormouse

Rote Liste NRW: G Gefährdung unbekannten Ausmaßes

  entry

Muscardinus avellanarius

The Hazel Dormouse is brown to ochre-coloured and has a completely furred tail. It is about as large as a House Mouse and lives in forests of all types and age classes, even pure spruce forests, park landscapes and riverine forests as well as hedges and shrubberies. In the Teutoburg Forest, the species populates mostly beech-old growth stands. From October to May, the animals hibernate in self-constructed nests on the ground or between rootstocks, sometimes also in nestboxes. During this they are unmistakably curled up with the tail placed around the body. In summer they produce artfully constructed nests at a height between 1 m and 33 m above ground, freely suspended in tall forbs, in the branches of woodlots or in tree cavities. They are constructed at low heights mostly in places with very dense vegetation, especially blackberries and raspberries. Hazel Dormice are usually philopatric and only active in the immediate vicinity of their nest. One animal builds 3 — 5 nests in a summer. During the summer activity period, one can usually observe two litters around the turn of the months June/July and July/August. The established litter size ranges from 1 to 9 young. Haze Dormice have a mostly vegetarian diet; however, in early summer up to 50 % of the food can consist of insects.

The distributional limit of the Hazel Dormice in NRW runs from the southwest to the northeast. The species occurs mainly in hilly or montane areas. It appears to become rarer towards the west. The scant records in the Rhineland probably are not just a result of low monitoring activity. The snow-rich higher elevation areas of the Eifel are apparently being avoided; in the neighbouring Belgium and in the Limburg Province (NL) the Hazel Dormouse is also very rare. In NRW the species is categorised as probably threatened (Category G). Additional knowledge regarding its further distribution can only be expected through regional efforts searching for species-typical gnawed hazelnuts.

Author

Peter Boye und Holger Meinig

Citation

Boye P, Meinig H (2025): Haselmaus (Muscardinus_avellanarius).In: AG Säugetierkunde NRW — Online-Atlas of the mammals of North Rhine-Westphalia. Downloaded from saeugeratlas-nrw.lwl.org on 2025/04/01