Within 24 to 36 hours after giving birth, the cycle repeats itself up to three litters per year. After three-weeks in the burrows, the kittens emerge and immediately start foraging on grasses and the bark of shrubs and trees, but continue to nurse for one more week. When the birth of the next litter is imminent, the kittens are on their own. But they leave the security of the burrow with all the defensive mechanisms required for survival above ground. From here they continue to emerge for foraging several times a day.
Growth is rapid.
At two months they are three-quarters of adult weight. By three months they are fully mature and capable of breeding. However, few on San Juan breed during their first year. Experts believe this a local survival measure to keep the population down. The runts either perish in the winter, recolonize abandoned warrens or dig new ones nearby.