How many offspring does a mouse produce? - briefly
A typical house mouse delivers 5–10 pups per litter, occasionally up to 12. Females can breed every 4–6 weeks, generating multiple litters per year and thus dozens of offspring annually.
How many offspring does a mouse produce? - in detail
Mice reproduce rapidly, typically delivering a litter of 5‑8 newborns after a 19‑21‑day gestation. The exact count varies with species, strain, age, nutrition, and environmental conditions.
- Laboratory strains (e.g., C57BL/6): average litter size 6‑7 pups; occasional litters reach 10‑12.
- Wild house mice (Mus musculus domesticus): average 5‑6 pups; maximum reported 12.
- Other Mus species (e.g., Mus spretus): average 4‑5 pups; upper limit 9.
Females become sexually mature at 6‑8 weeks and can breed every 4‑5 weeks. Assuming optimal conditions, a single female can produce:
- Three litters per year: 15‑24 offspring.
- Four litters per year: up to 32 pups, observed in controlled environments with abundant food.
Reproductive output declines with age; after the third or fourth litter, litter size commonly drops by 1‑2 pups. Male contribution does not limit litter size but influences breeding frequency through territorial and mating behaviors.
Key factors influencing pup number:
- Genetic background: selective breeding for high fecundity increases average litter size.
- Nutrition: high‑protein diets raise both litter size and survival rates.
- Photoperiod and temperature: longer daylight and moderate temperatures enhance reproductive cycles.
- Health status: disease or parasite load reduces litter size and may increase embryonic loss.
Overall, a healthy mouse can generate between 15 and 30 offspring annually, with the potential to exceed 30 under ideal laboratory conditions.