When do mice go into hibernation? - briefly
Most mouse species remain active throughout winter, finding shelter and food instead of hibernating. Only a few wild varieties enter short periods of torpor during the coldest months.
When do mice go into hibernation? - in detail
Mice enter a state of reduced metabolic activity during the coldest months of the year, typically when ambient temperatures fall below 5 °C (41 °F) for an extended period. This physiological shift is triggered by decreasing daylight length and the depletion of food resources, prompting the animal to conserve energy.
The onset of this dormant phase varies among species:
- Common house mouse (Mus musculus): Rarely hibernates; may seek indoor shelter when temperatures drop.
- Wood mouse (Apodemus sylvaticus): Begins torpor in late autumn, often November, continuing through winter until temperatures rise above 10 °C (50 °F).
- Deer mouse (Peromyscus maniculatus): Initiates hibernation in October–December, emerging in March–April as ambient warmth returns.
Physiological changes during this period include a drop in core body temperature from ~37 °C to 5–10 °C, heart rate reduction from 600–800 beats/min to 10–20 beats/min, and a metabolic rate decline to 2–5 % of normal. Fat stores accumulated in late summer provide the sole energy source; mice consume roughly 1 g of stored fat per day.
Termination of the dormant state occurs when external temperatures consistently exceed 10 °C, daylight length increases, and food becomes available. Mice resume normal activity, rewarming their bodies, increasing heart rate, and resuming foraging behavior.