Reproductive life history correlates of early and late sexual maturation in female Mongolian gerbils (Meriones unguiculatus)

Age at vaginal introitus is bimodally distributed in female domesticated Mongolian gerbils; some exhibit vaginal perforation before eye-opening (day 16), others after weaning (day 25). We found early- and late-maturing female gerbils to differ significantly in reproductive life history. Early-maturing females first reproduced when younger, had more litters, with more young per litter, and consequently had more than twice as many offspring as …