Gray squirrels breed twice a year, December to February and May to June, though this is slightly delayed in more northern latitudes. The first litter is born in February to March, the second in June to July. There are normally two to six young in each litter, but this number can be as high as 8. The gestation period is about 44 days. The young are weaned at 7 weeks and leave the nest after 10 weeks. The eastern gray squirrels can start breeding as early as 5 and a half months old, but usually breed for the first time at the age one year old. These squirrels can live to be 20 years old in captivity, but in the wild usually only live up to 12 years.