How many offspring do mice produce? - briefly
A typical mouse litter contains 5–12 pups, averaging about 6–8. Under favorable conditions a female can have multiple litters each year, yielding dozens of offspring annually.
How many offspring do mice produce? - in detail
Mice typically give birth to a litter of five to twelve pups. The exact number varies with species, strain, and environmental conditions.
- Laboratory strains (e.g., C57BL/6, BALB/c): average 6–8 pups; some lines reach 12–14.
- Wild house mice (Mus musculus): average 5–7 pups; occasional litters of three or up to ten.
- Extreme cases in selective breeding: reported litters of 15‑20 offspring.
Key factors influencing litter size:
- Genetics: selective breeding can increase or decrease average pup count.
- Maternal age: young females (first parity) often have smaller litters; peak productivity occurs at 3–6 months.
- Nutrition: protein‑rich diets raise average litter size by 1–2 pups.
- Season and photoperiod: longer daylight periods correlate with larger litters in wild populations.
- Parity: each subsequent pregnancy generally yields more pups until senescence reduces fertility.
Reproductive cycle details:
- Gestation: 19–21 days.
- Post‑partum estrus: females become fertile within 24 hours after delivery.
- Inter‑litter interval: 21–28 days under optimal conditions.
Potential annual output per female:
- Up to ten litters per year in laboratory settings, resulting in 60–80 offspring.
- In the wild, limited by food availability and predation, typical annual production ranges from 30 to 50 pups.
Male fertility:
- Mature males produce viable sperm from 6 weeks of age.
- A single male can mate with multiple females, contributing to high population growth rates.
Overall, mouse reproduction is characterized by short gestation, rapid return to estrus, and relatively large litters, enabling a single female to generate dozens of offspring annually under favorable conditions.