Where do field mice winter? - briefly
Field mice spend winter in insulated nests built in underground burrows, within dense ground cover such as leaf litter, hedgerows, or the base of shrubs, where they remain insulated from cold and predators. They may also occupy abandoned rabbit or vole burrows that provide stable temperatures and protection.
Where do field mice winter? - in detail
Field mice survive the cold season by occupying insulated microhabitats that buffer against low temperatures and provide access to limited food resources. Their primary refuges are self‑excavated burrows located deep enough to maintain temperatures above freezing. These tunnels often extend several meters underground, with side chambers lined with dry grasses, leaves, and shredded plant material that retain heat and moisture.
Additional winter shelters include:
- Hedgerow thickets and dense vegetation: Thick stems and leaf litter create a protective layer that reduces wind exposure and conserves warmth.
- Barns, sheds, and other human structures: Cracks in foundations, insulation gaps, and stored hay offer stable microclimates and occasional food scraps.
- Rock crevices and fallen logs: Natural cavities retain residual heat from solar exposure and provide dry nesting sites.
- Underground nests beneath snow cover: Snow acts as an insulating blanket, allowing mice to remain in shallow burrows while maintaining a relatively constant temperature.
During winter, field mice reduce metabolic activity and limit movements to conserve energy. They rely on stored seeds, grains, and plant remnants collected earlier in the season. In regions with severe frost, individuals may enter a state of torpor, lowering body temperature and heart rate to further decrease energy demands. Population density influences site selection; high competition can force some individuals to occupy marginal habitats such as abandoned rabbit warrens or the lower sections of hedgerows.
Overall, the wintering strategy of field mice combines deep burrowing, utilization of vegetative cover, and opportunistic use of anthropogenic structures to ensure survival until spring temperatures allow for increased foraging and reproduction.