Sugar gliders are small nocturnal marsupials and usually have one or two babies at a time. The babies (called joeys) are born underdeveloped after a typical pregnancy of 15 to 17 days. They grow into a miniature version of their parents in their mother's pouch after about four months, when they are large and developed enough to start life on their own. The male stays with the female to care for and protect her and the young until the joeys are mature enough to care for themselves.
The Gestation Period
Like other marsupials, the gestation period of sugar gliders is very short, lasting only 15 to 17 days. During this time, the mother should be given more food than usual since her dietary needs increase. For much of the gestation period it is impossible to see any physical signs of pregnancy, but there may be changes in the mother's behavior. A pregnant sugar glider may become more restless and less friendly. A peaceful location with few disturbances is important to keep her stress level to a minimum and promote a healthy pregnancy.
Birth and Migration to the Pouch
Sugar glider babies are born very underdeveloped with their pink skin exposed. Their eyelids are fused shut as their eyes continue to develop. Their ears are also fused shut and look like tiny nubs on either side of their head. They measure about 0.2 inches and weigh about 0.007 ounces. Immediately after birth, the baby makes its way up the mother's abdomen and into the pouch. Unable to see or hear, the baby must rely on instinct alone since the mother is unable to help it. Arriving safely into the pouch takes about five minutes, but if the baby loses its grip, the mother can't assist it and the result is often fatal.
Once a baby crawls into the pouch, it finds one of the four nipples. The baby does not yet have jaw muscles developed enough to suckle milk by itself. Instead, the nipple swells in its mouth making the baby attached in place. It will remain "stuck" until it is more developed.
A small swelling of the pouch may become visible about two to three weeks after the babies are born. It is still best not to disturb the mother, but an experienced person could gently palpate the abdomen to see how many babies are there.
About six weeks after migrating to the pouch, the babies' jaw muscles are developed enough to disengage from the nipple and suckle at will. The mother's abdomen appears bigger. Roughly two weeks later, it may be possible to glimpse a part of the tail or limb peeking out of the pouch. About 10 weeks after birth joeys are able to eat solid food and leave their mother's pouch for very brief meals. Their main source of nutrition, however, is still milk.
Leaving the Pouch
Joeys leave the pouch about four months after moving into it. They weigh less than an ounce at this stage. Most joeys are reluctant to permanently leave the pouch and stay there until they are too big to fit in it. They climb out tail first, but may try to leave their head in the pouch for a long time after that (sometimes as long as a day or two). The joeys' body is covered with fur that is lighter and shorter than that of an adult. Their eyes are often still closed and only open about 10 days after they emerge. They will ride on the back of either parent and continue to suckle until the age of five months, when they are ready to start life on their own.