How often does a field mouse give birth? - briefly
Field mice reproduce continuously throughout the breeding season, delivering a litter about every three to four weeks, which allows a female to produce five to six litters in a year.
How often does a field mouse give birth? - in detail
Field mice (genus Apodemus) reproduce multiple times each year. The breeding cycle is driven by temperature, daylight length, and food availability, allowing several litters during the warm months.
Gestation lasts 19–21 days. After weaning, females can become fertile again within a few days, enabling rapid successive pregnancies. In temperate regions, the typical breeding season runs from early spring (April) to late autumn (October). Within this period, a female can produce:
- 3 to 5 litters per season, sometimes up to 6 in optimal conditions.
- 4 to 8 offspring per litter, with an average of 5‑6.
The total number of young born to a single female in one year therefore ranges from about 12 to 30, depending on climate, habitat quality, and population density. In colder climates or during harsh winters, breeding may be limited to 2–3 litters, reducing annual output accordingly.
Reproductive frequency is also affected by:
- Food abundance: plentiful seeds and insects accelerate ovarian cycles.
- Predator pressure: high predation can shorten the breeding season.
- Age: first reproduction occurs at 6–8 weeks; older females may experience a decline in litter size.
Overall, field mice are capable of producing several litters annually, with each gestation lasting just over three weeks, resulting in a high potential reproductive rate under favorable environmental conditions.