How many mice are born at one time by a house mouse? - briefly
A house mouse typically produces a litter of five to eight young, averaging about six pups per birth.
How many mice are born at one time by a house mouse? - in detail
House mice (Mus musculus) typically give birth to a single litter containing between five and twelve pups. Laboratory strains commonly produce six to eight offspring per delivery, while wild populations often reach the upper end of the range, with occasional litters of fourteen reported in favorable conditions.
The mean litter size for the species hovers around seven pups. Studies of mixed‑sex colonies in controlled environments report an average of 7.2 ± 1.5 individuals per birth, whereas field surveys of urban and rural settings indicate a slightly higher mean of 8.1 ± 2.0.
Litter size varies according to several biological and environmental parameters:
- Female age: prime‑reproductive females (2–4 months) produce larger litters than juveniles or senescent individuals.
- Nutritional status: protein‑rich diets increase pup numbers by up to 20 % compared with calorie‑restricted feeding.
- Genetic background: inbred laboratory lines tend toward lower variability, while outbred or wild‑derived stocks display broader ranges.
- Seasonal cues: longer daylight periods and warmer temperatures correlate with modestly larger litters, reflecting increased resource availability.
Research data illustrate these trends. A 2015 laboratory investigation recorded 6–9 pups per litter in C57BL/6J mice fed a standard chow, with occasional extremes of ten. Field work in European cities (2018) documented 5–12 pups per litter among feral populations, with a maximum of fourteen in a suburban garden where food waste was abundant.
Gestation lasts 19–21 days, and females can become fertile again within 24 hours after parturition. Under optimal conditions, a single female may produce five to six litters annually, resulting in a potential output of 35–70 offspring per year. High reproductive capacity contributes to the species’ rapid population expansion in human‑occupied habitats.