Atlas der Säugetiere Nordrhein-Westfalens

Zwergmaus

705 entries

Harvest mouse

Rote Liste NRW: G Gefährdung unbekannten Ausmaßes

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Micromys minutus

With 5 to 7.5 cm body length and a weight of 7 to 14 g, the Harvest Mouse is one of the smallest European rodents. The tail of the light brown to ochre coloured animals adds another 4.5 to 7.5 cm. Since these small animals are too weak to construct tunnels or burrows in the ground they have entered another habitat, the forest of stems as it appears in the form of wet meadows and grain fields. In dense stands of vegetation the Harvest Mouse builds a nest, mostly from grass (preferably reed canary grass) attached to vertical stems. For this purpose, leaves that are at first still attached to the stem are spliced with the incisors and woven together. As soon as the basic structure is completed other leaves are clipped and worked into it until a dense sphere with a diameter of 7.7 to 9 cm is created. Harvest Mouse nests have been found at heights of 20 cm to 1.7 m. The Harvest Mouse retreats into these nests during periods of rests and in them it gives birth to its young. In their habitat Harvest Mice have to be good climbers. To free the forefeet for nest construction, food searches and other activities, they use their tail as an additional prehensile organ. Harvest Mice are constantly in search of a structure that they can grasp with their tail. They can also hang for an extended period exclusively from their tail. In spite of all climbing ability Harvest Mice cannot grasp stems with a diameter of over 7 mm with their feet, which is why they are not found in pure stands of reed. In autumn, when the grasses die, Harvest Mice have to come to the ground. Because they don′t burrow, they search for hiding places in beds of straw and barns or utilize the abandoned burrow systems of other rodents. Not much is known about the winter phase of the life cycle of Harvest Mice. In Central Europe the Harvest Mouse feeds mainly on grass seeds and leaves as well as insects and their various life stages.

Based on the topographic sheet quadrants an area-wide occurrence of the Harvest Mouse in NRW is likely. The attachment of the species to mostly wet and relatively nutrient-poor habitats with a narrow stem diameter, which increasingly disappear from the landscape as a consequence of the intensification of agriculture, suggests a decline of the populations of the species, but detailed monitoring data are not available.

Author

Holger Meinig

Citation

Meinig H (2024): Zwergmaus (Micromys_minutus).In: AG Säugetierkunde NRW — Online-Atlas of the mammals of North Rhine-Westphalia. Downloaded from saeugeratlas-nrw.lwl.org on 2024/12/21