The gestation period for a gerbil is 24-28 days. If the gerbil is nursing, however, she will delay implantation of the embryos. This gives her enough time to wean the current pups before the next litter arrives.
This causes the gestation period for nursing gerbils to be a bit longer, 30-43 days.
Early in the pregnancy you will not be able to tell that your gerbil is pregnant. The babies are still too small to be noticeable. About day 18, you may notice that your gerbil is looking a bit "bulky". If she is currently nursing, however, this slight change may not be noticeable because her body hasn't gotten the chance to return to a pre-pregnancy state.
At about day 20-23, your gerbil will begin to look more pregnant. If you still are questioning whether she is pregnant, you can usual tell by the "hand test". This just involves setting the gerbil on your hand and seeing if her belly brushes your palm. In the normal, non-pregant state, her belly will be lifted slightly off your hand. When she is pregnant, however, you can definately feel the light weight of her stomach touching your palm.
Very late in the pregnancy, day 24-28, your gerbil will feel very large and look pear-shaped. There is no question that she is pregnant at this point! Some people say that the female feels lumpy, like a little sack of potatoes. I've never noticed this, but you may. Whatever you do do not press on her belly to "feel" the babies. This is very uncomfortable for your gerbil and cannot be good for the developing pups. Please don't count your chickens before they've hatched!
Of course if the litter is really small, you might not be able to tell that your gerbil is pregnant. In the pictures below, Indira, my gerbil, was carrying either 5 or 6 pups. Also keep in mind, however, that some gerbils will balloon out with only three pups, while a litter of six may still look fairly small.
In the last few days of pregnancy, you may notice the babies moving. It will look like the side of your gerbil is rippling. This motion is most noticeable the day of the birth.
|21 days pregnant
(30 days pregnant if nursing)
|25 days pregnant
(35 days pregnant if nursing)