The common names for wildlife are ubiquitously confusing - and the possum vs opossum debate is the perfect example. So, which is correct? That depends on what continent you’re on!
The Virginia opossum is the only marsupial found in the United States and Canada. Marsupials are a type of mammal that gives birth to offspring prematurely and often carry them in a pouch, unlike humans and all other mammals in North America who are placental mammals. When fetal Virginia opossums are born, they are no larger than a honey bee and must crawl to the safety of their mother’s rudimentary pouch, where they remain for up to two months before being carried around on her back. While colloquially, many people refer to them as ‘possum,’ the technical name is ‘opossum.’ There is a broader diversity of opossums that are all endemic to Central and South America and belong to the same order, Didelphimorphia. In Australia, where virtually all mammals are marsupials, similar-looking species are called ‘possums’ and belong to the order Diprotodontia, which also includes kangaroos and koalas.
Opossums are nocturnal and rare to see, which is why it may be surprising to actually see one and realize they do live in southern Arizona. I swore I saw an opossum in Chiricahua National Monument as it ran across the road earlier this year, and no one else in the car believed me, so it was exciting to come across visual proof a few months ago on one of the BWP wildlife cameras.
This species is the North Mexican opossum (Opossum virginianus californica), one of four subspecies. We are lucky enough to coexist with these unique animals, as they only inhabit the very edge of the US/Mexico border and live as far north as Tucson. The other three subspecies live in the Eastern United States, and their range has been steadily expanding from Florida to as far north as Ontario.
Similar to raccoons and coyotes, opossums are exceptionally adaptable animals and have learned to coexist with humans, which explains their ever-growing habitat range. This can be partly attributed to their opportunistic feeding style, meaning they’ll eat most anything they come across, including birds and their eggs, fruit and grasses, rodents, reptiles, garbage, and pet food. While they may have a bad reputation as nuisance animals that get into your attic and trash cans or carry rabies, they are actually quite beneficial. The Virginia opossum has a low average body temperature that is lower than usual, meaning it is rare for them to harbor diseases like rabies. They also help keep rodent and insect populations in check.
One of the Virginia opossum’s most iconic skills is going into a state of thanatosis, or playing dead, which is an involuntary reaction when they feel threatened, and the origin of the phrase ‘playing possum.’ They go still, sometimes drooling or having their tongue hang out of their mouth, to appear as unappetizing as possible. Despite their best efforts to look dirty and deranged, they are cute creatures who are important, unique members of the borderlands ecosystem who just need a bit of PR help.