Opossums reproduce multiple times per year, with most females having 3 different litters per year, each with as many as 13 young. The gestation period for opossums is only 12-13 days.
At time of birth, opossums are incredibly small, each one weighing only about 2 ounces. For example, all 10 babies in the photo below weighed a total of only about 10 ounces. That means each one of them was about the same weight as a U.S. quarter!
Baby opossums are nearly helpless at birth and will require another 2 months of development inside the mother’s pouch before they are ready to venture out into the world on their own.
Birth Process
After mating, the female opossum will build a nest in a protected location. Here are some of the typical places where an opossum might make its nest:
Hollow tree
Stump
Brush pile
Under a porch
After her short gestation period is complete, the female opossum will typically give birth to as many as 13 offspring, although litters of 6-8 young opossums are most common.
When an opossum gives birth, her offspring will be pink, hairless and totally blind, weighing only about two ounces. Because they are undeveloped at birth, the mother must transfer them with her mouth or nose to her pouch, where they will live and continue developing for the next two months.
For the first 50-60 days after birth, baby opossums will live inside the mother’s pouch. During this time, they will primarily nurse from her. By the time they are 4 weeks old, the opossum’s eyes and ears will have opened and they will have fur covering their bodies.
Raising Young
After 60-90 days inside their mother’s pouch, baby opossums will typically begin to emerge. They will ride piggyback on the mother’s back for the next 2-3 months. After 100 days, they will be weaned.
The young opossums will remain with their mother until the time she gives birth to another litter. At that point, they will be about 10 months old and will be able to fend for themselves.
Why Do Opossums Have So Many Babies?
Opossums have a high rate of infant mortality – roughly 50%. So, having multiple litters with up to 13 offspring helps to ensure the survival of the species.