Species Portrait: Opossum
12/3/2018 10:15:59 AM
From MDWFP
Opossums can turn up almost anywhere in Mississippi, and it is likely that someday you may come face to face with one. The Virginia Opossum (Didelphis virginiana) is the only marsupial in North America. Opossums are the size of a dime at birth. They live in their mother's pouch for the next 2.5 months, nursing in a completely dark world. Once they are large enough to leave the pouch, the baby opossums climb onto mom’s back where they hitch a ride for another month or two before venturing off on their own. Each litter can produce more than 20 babies while eight to nine per litter is more common. Adult opossums generally grow to be the same size as a house cat, approximately 10-13 pounds. Opossums have a short lifespan compared to other mammals, usually only surviving one or two years in the wild.
You have probably heard that opossums are dangerous, carry rabies, and will get into the trash. Only one of those is true. Instead of attacking, their defense mechanism is to open their mouths and start hissing. If that is not enough to scare you away, they will then fall over pretending to be dead, which is how the phrase “playing possum” was introduced. They can also use glands to create a foul-smelling fluid to further ward off predators. Opossums can do all of this while staring into space with their tongues hanging out. This can last for hours, but they usually will take the first opportunity to escape. Opossums are also one of the safest wild animals to have around because marsupials are highly resistant to rabies, and it would be an extremely rare event for an opossum to contract the disease. What is true about an opossum is that it will never pass up the opportunity to look for a delicious treat in the trash can. Each opossum eats 90 per-cent of ticks it comes in contact with and individually kills approximately 5,000 in a single season. Opossums also eat anything else they can find, acting like vacuum cleaners for the environment and will happily feed on carrion. An opossum will also eat fallen fruit, insects, grubs, mice, and snakes. They even eat venomous snakes like copper-heads, as they are immune to the venom, most likely because of their low body temperature and metabolic rate.
Opossums are one of the only animals outside the primate family to have opposable thumbs. The only other mammals are Koala, Giant Panda, and Waxy Monkey Leaf Frog. Opossums even have twice as many oppos-able thumbs as humans because they have them on their back feet too. Opossums love to climb and use their long, prehensile tail to wrap around limbs and help them balance. Cartoons have taught us that opossums hang upside down by their tails while sleeping in trees. This is not true. Baby opossums can hang upside down for a short time, but as they grow, their body weight becomes too much for the tail to support. As one of the world’s oldest mammals, opossums were walking the earth back in the Upper Cretaceous Period when dinosaurs were still common. This ancient mammal is still a wonder of our world today, so give the next opossum you see a second chance.
Andrea Falcetto is the Education Coordinator for MDWFP’s Mississippi Museum of Natural Science
