Alaska Vole

Northern red-backed voles can breed up to four times per year. Young are born May-September and probably average two litters per year. Litter sizes are between four to nine, and average about six. About 20 percent of females from the first litter breed during the summer of their birth; the remaining 80 percent and later litters breed the following May.

Gestation is 17–19 days. Young are weaned in 12–17 days and are mature in two to four months. Little is known about their reproduction strategy in the wild, but voles have displayed a polygynous mating system in captivity.