While their strange appearance and unusual habits, Virginia opossums (Didelphis virginiana) are one of our most interesting mammals. They are the only marsupials found in North America and their range is expanding.
With their hairless, prehensile (grasping) tails and exposed ears, opossums are not adapted for cold weather. As we experience warmer and warmer winters, opossums are found increasingly further north—as far north as Maine today. They’ve also been introduced to the West Coast, possibly for food during the Great Depression.
On a visit to Marshy Point, our resident opossum can be observed in her habitat on the back deck. Along the trails, if there is mud or snow, opossum tracks are often visible. Their tracks are one of the most recognizable mammal tracks—with opposable thumbs on their back feet and an almost star shaped front footprint.
A look inside our opossum’s food bowl reveals one reason why the species is so successful and widespread: they are omnivores who are very adaptable and will eat almost anything. To eat their highly varied diet, opossums have 50 teeth—more than any other North American land mammal.
Another reason for their success is their high rate of reproduction. A female opossum has space for thirteen babies in her pouch. As the babies grow larger they move from the mother’s pouch to her back, where they are carried along.
Perhaps the opossum’s most famous behavior is “playing possum.” This appears to be an involuntary state resulting from fear and is not a behavior observed in captive animals.
Despite all of their amazing adaptions, opossums also have surprisingly small brains for their size and short lifespans. Wild opossums usually only live a year or two and captive animals might make it to three or four.
Opossums carry few diseases and do not generally contract rabies due to their low body temperatures. They do, however, have a taste for ticks and are beneficial in getting rid of these potentially disease-causing parasites.
So the next time you encounter an opossum—or evidence that one has been around—consider all the adaptations that make them one of North America’s most widespread and interesting mammals.