How many offspring does a mouse have? - briefly
A mouse typically produces 5–12 pups per litter, with an average of 6–8. Depending on species and conditions, females can have several litters annually, often totaling 20–30 offspring per year.
How many offspring does a mouse have? - in detail
Mice are prolific breeders. A single female generally produces a litter ranging from three to eight pups, with the average in laboratory strains being five. Wild house mice (Mus musculus) often have slightly smaller litters, typically four to six, reflecting environmental constraints.
Key factors that modify litter size include:
- Genetic background: Inbred laboratory lines such as C57BL/6 may yield consistently smaller litters (4‑5) than outbred stocks, which can reach eight or more.
- Age of the dam: First‑time breeders (5–6 weeks old) commonly have fewer offspring; peak productivity occurs between 8 and 12 weeks, after which litter size gradually declines.
- Nutrition and health: Adequate protein and caloric intake support larger litters; disease or stress reduces reproductive output.
- Season and photoperiod: In wild populations, longer daylight periods correlate with increased fecundity.
Reproductive timing further amplifies output. The gestation period lasts about 19‑21 days. After birth, females can become pregnant again within 24 hours, a phenomenon known as postpartum estrus. Consequently, a healthy mouse can produce 5‑7 litters per year, resulting in a potential total of 30‑50 offspring over its reproductive lifespan.
Male mice contribute indirectly; a single male can sire litters for multiple females simultaneously, enhancing overall population growth. However, sperm quality declines with age, affecting the viability of later litters.
In summary, a mouse typically yields five young per birth, with the capacity to generate dozens of progeny annually under optimal conditions.