BY CONSTANCE CASEY
Opossums, animals that can eat almost anything, are increasingly joining their fellow omnivores at the suburban garbage can buffet. Opossums are shy, shambling creatures—the opposite of aggressive—but an opossum on its nocturnal foraging rounds often elicits a scream of disgust or fear. People tend to see them as ugly and vicious because their tails are bare and their narrow snouts are full of sharp teeth.
An opossum’s tail is ratlike, bald, and scaly. But to think of them as large rats or naked-tailed squirrels is wrong. Opossums, commonly known as possums, are not rodents; they are marsupials. The fact is that they’re North America’s only pouch-bearing animals. (Marsupium is “pouch” in Latin.) The world’s most famous marsupials, kangaroos and koalas, are Australian and cute. (Possums Down Under are in a different family, the Phalangeridae, and have appealing, furry tails.)
The western hemisphere has about 100 opossum species, all in the family Didelphidae. Of these, only one, the Virginia opossum (Didelphis virginiana), lives in North America. When the land bridge linking South and North America formed three million years ago, some opossums trudged north. By the 1600s the creature that would be the Virginia opossum had traveled up to the Virginia colony. There, Captain John Smith of Jamestown observed, “an opassum hath an head like a Swine and a taile like a Rat….” (He derived the name “opassum” from an Algonquin word.) Smith correctly observed that the animal carried its young in a pouch.