Female southern grasshopper mice become receptive at 6 weeks and are able to produce up to 6 litters in a year, but their reproductive life is short, few breeding in their second year.
Female southern grasshopper mice become receptive at 6 weeks of age and give birth to their first litter when four or five months old.
Southern grasshopper mouse gestation lasts 26-35 days, with an average of 29 days. Litter size ranges from one to six young with an average litter size of 2.6-4.
Young females apparently have significantly greater reproductive potential
than old females. They are able to produce as many as six litters in a year in the wild, but their reproductive life is short, few breeding successfully in their second year. Females tend to be sexually active only during one breeding season, which is due to their rapid reproductive aging following their first year.
Female southern grasshopper mice born as early as April may produce two or three litters before the year’s end, but females born in late summer may have as many as six litters during the following breeding season.