07/31/2014 09:50 am ET Updated Dec 06, 2017

"Miracle" Baby Opossums Survive Despite Incredible Odds

Orphaned opossums at WildCare. Photo by Kate LynchThis little brother and sister pair went through an ordeal that should have taken their lives. But somehow they survived.

A WildCare member in West Marin, California stopped her car to check if a dead Virginia Opossum on the side of the road was a female with babies in her marsupium or pouch.

Sometimes the mother's marsupium will protect her babies, even if she is killed, but the best chance of survival exists if the mother's body is brought to the Wildlife Hospital very quickly after the collision.

The accident that killed these babies' mother must have happened more than a day ago, however, so there was little hope of finding any surviving pups.

Imagine WildCare Medical Staff's surprise to find two bright, healthy, completely unharmed little babies hidden deep in the pouch!

If you see a road-killed Virginia Opossum on the side of the road, WildCare recommends checking to see if it is a female with babies on board (but only if it is safe for you to do so!)

The protective abilities of a marsupial's pouch are astonishing, and nothing better illustrates that than the survival of this little opossum pair.

The force of the collision probably killed the mother opossum instantly, and the other siblings in the pouch were also killed by the impact. These two babies must have been deeply ensconced in the pouch, and only the protective shield of their mother's body kept them alive. That they remained alive in the pouch for the day or more after the accident, and that their rescuer knew to stop, check, and ultimately transport the mother's body to WildCare is truly something of a miracle.

Showing this young opossum's marsupium. Photo by Alison HermanceOpossums are unique to North America-- they are our only marsupial mammal. Opossum babies are born incredibly tiny, only the size of a raisin, and very under-developed. Using vestigial arms they climb from the mother's birth canal up her belly and into the marsupium where they latch onto a nipple. Unlike other mammals, baby marsupials complete much of their development external to the uterus.

Once the babies reach 100 - 125 grams in weight, they start exploring outside the pouch and using their incredibly grippy little paws to climb up on and cling to their mother's fur as she patrols her territory in search of food. Eventually they lose their grip, ideally once they are at least the size of a softball from nose to base of tail, and they are then on their own. This is the opossum's dispersal strategy. These babies are at the size where they would be starting to explore outside the pouch, so it was lucky they were inside when their mother was struck.

These two siblings are too small to be on their own, and will remain in Foster Care at WildCare to grow up together until they are big enough to be released back to the wild. Although they still enjoy formula licked from a syringe, it's nearly time to wean these babies and get them accustomed to solid foods.

What do you offer a weaning baby opossum? A tasty combination of chopped up fish, egg and fruit-flavored yogurt, all mixed together, of course.

Watch this brother and sister pair discover the joys of fish-flavored fruit yogurt in this video below, taken by opossum Foster Care specialist, Kate Lynch.