How many offspring does a mouse give birth to at one time? - briefly
A mouse typically delivers a litter of five to twelve pups, averaging about six to eight offspring. Litter size can vary with species, age, and environmental conditions.
How many offspring does a mouse give birth to at one time? - in detail
The average litter of a common house mouse (Mus musculus) contains 4 to 7 newborns. Laboratory strains often produce 5 or 6 pups, while wild populations may range from 3 to 9, with occasional litters exceeding 10 under optimal conditions.
Factors influencing litter size include:
- Genetics: Certain strains are bred for larger or smaller litters.
- Maternal age: Younger females (first estrus) typically have smaller litters; peak productivity occurs at 3–6 months.
- Nutrition: Adequate protein and caloric intake increase pup numbers; deficiency reduces them.
- Environmental stress: High density, predators, or extreme temperatures can suppress reproductive output.
Gestation lasts 19–21 days, after which the female delivers the entire cohort within a single birthing event. The newborns are altricial: blind, hairless, and dependent on maternal care for the first 3 weeks. Litter frequency averages 5–7 times per year in temperate climates, allowing a single female to produce 20–40 offspring annually under favorable conditions.