Petaurus breviceps or better known as Sugar gliders are truly unique when it comes to their reproductive system. Females have 2 uterus and the males accommodate that uniqueness in the female by having a bifurcated penis which enables him to inseminate one or both of the females uterus.
Females have an estrous cycle of approximately 29 days. In their natural habitat, the young are born only from the months of June to November but in captivity Sugar Gliders can breed continuously approximately every 3 – 4 months under optimum conditions which involve a diet higher in protein than their normal staple food provides.
Gestation usually lasts around 16 days then at that time, the female will lick a wet trail from her pouch to her cloacae area and proceeds to give birth to a joey that is the approximate size of a grain of rice and does not even resemble a Sugar Glider! Then the little grain of rice follows the lick trail that their mother made, finds its way to her pouch, crawls in and attaches to a teat.
Sugar gliders usually have a litter size of 1-2, but can have up to 4 joeys at a time. Each joey will weigh approximately 0.19 grams at birth. The young first leaves the pouch after 65 - 70 days, and will be weaned in approximately 75 - 111 days after that. In their natural habitat, females will not become pregnant again until their joeys are weaned and leave the nest but in (Grove, 1996; Nowak, 1997) captivity it is common to see females nursing one or two almost weaned joeys with new “ joey bumps” already showing in her pouch.
Many things can happen during any one of these steps in the reproduction process that can cause a joey to fail to thrive. Most reasons are unknown to us and can only be chalked up to nature’s way of weeding out the weak or sick. But I know first-hand how very disturbing it is to come in one evening and find the remains of a cannibalized joey at the bottom of the cage. You second guess yourself over and over trying to figure out what “you” did to cause this but in truth, it may not have been you at all. Most times we will never know. But first and foremost, NEVER blame the gliders! This is a very natural process for them because in the wild it is a necessity to clean up the remains so their predators will not find their nest. Also, don’t just assume they “killed” the joey. Many just die and then mom and dad simply are forced to “clean up the mess”.
In the case of my gliders, the 2 times in my 5 years of breeding that I have lost a joey, each pair became upset and then depressed. First exhibiting an almost panicked “freaked out” behavior and then proceeded by a few days of not eating. Whether I am anthropomorphizing or not, I believe they mourn the loss as well.
So please those of you who are considering breeding in the near future, consider all aspects of it and make sure you can accept the good with the bad before proceeding.