Female gerbils reach mating maturity at approximately 9 to 12 weeks of age. They experience spontaneous ovulation and breed year-round. Male and female gerbils pair and mate for life and will co-parent their brood once babies are born.
A female gerbil is pregnant for approximately 25 to 30 days, after which she typically gives birth to a litter of about a half-dozen babies -- though first litters are sometimes smaller. Unlike some other rodent breeds, you have no need to remove the male gerbil from the cage when the mother gives birth, as the father will actively help in the process. It is important to note, however, that as many as 85 percent of all new gerbil mothers will be ready to breed again immediately following birth, so if you don’t want an additional litter, you will have to separate the male into another habitat.
Involved Gerbil Dad
The gerbil dad will be an active participant in raising the young gerbil pups. The father will help from the time the pups are born until they reach weaning age at about 21 days. At that point, you can gradually switch the babies to a diet of commercial pellet food. You can house siblings together initially, but separate them if aggressive behavior takes place. Most gerbils do best when housed with one or more littermates of the same sex.
Prevent Unintentional Breeding
Separate gerbil littermates from their parents and from each other before they reach breeding age to guard against unintentional mating. You can differentiate the males from the females by lifting their tails and assessing the perineum distance -- if the urinary opening is close to the anus, the gerbil is a female; a greater distance between the two indicates a male. You may also be able to identify testicles in males, though they are sometimes underdeveloped when the animal is young.
While nest abandonment and cannibalization is rare in gerbils, it can and does happen. If the mother gerbil is unable to care for her babies, or attempts to kill them, you should separate them from her and attempt to nourish the babies with a kitten milk replacement. Contact your vet for advice on the best way to proceed if this becomes a necessity. Your vet will take into consideration the circumstances and the age and size of the babies and make recommendations for keeping babies warm and well-fed.
- Ryan McVay/Lifesize/Getty Images