Are Opossums Endangered? (+ 7 Neat Facts About Opossums)

close up of cute opossum - are opossums endangered

Are opossums endangered? Well, it depends on which kind of opossum you’re talking about. There are actually more than 60 species of opossum, which are more or less threatened. 

They’re all part of the Didelphidae family of marsupials. Fortunately, most species in the family have healthy populations. The one we most commonly think of, the Virginia opossum (Didelphis virginiana), is actually spreading. The Virginia opossum, also called the common opossum, originated in tropical regions and its range is expanding further north as climate change warms the planet.

Not every species of opossum has fared as well, though. Here are a few opossums you may not have heard of and where they sit on The International Union for Conservation of Nature (IUCN) Red List of Threatened Species

The Red List uses levels to denote how threatened a species is. From least to most endangered, those levels are: least concern, near threatened, vulnerable, endangered, critically endangered, extinct in the wild and extinct. All information about locations and population trends is from the Red List.

Near Threatened

Chacodelphys formosa is only found in the Formosa province of northern Argentina. Its populations are declining due to deforestation. 

Possibly the smallest living opossum, Chacodelphys formosa’s body is only 68mm long (about the length of a person’s index finger!), with a 55mm long tail. Researchers describe it as grey brown with a narrow mask of dark fur around the eyes and a tail that’s dark on top.

Native only to eastern Paraguay and nearby Mato Grosso do Sul in Brazil, the Paraguayan fat-tailed mouse opossum (Thylamys macrurus) population is declining. It lives in shrubby savanna, subtropical and deciduous forests. Its forest habitats are threatened by logging and clearcutting for agriculture, which puts Thylamys macrurus at risk. 

Researchers describe this opossum as medium-sized (at 11.3-12.24 cm, excluding the tail), “corpulent” and greyish-brown, with lighter flanks and underbellies and dark rings around the eyes. A neat fact about this animal is that it gets its name from its tail, which stores fat when food is plentiful.

Vulnerable

The dryland mouse opossum (Marmosa xerophila) is found only in northwestern Venezuela and northeastern Colombia, around Lake Maracaibo and the Gulf of Venezuela. This little creature could fit in your hand and has dark smudges around its eyes and brownish fur with a lighter underbelly. Their habitat is quickly fragmenting, and their populations declining. Deforestation and urban development are the biggest threats to Marmosa xerophila

Junin slender opossums (Marmosops juninensis) live only in the forests of the Chanchamayo Valley, Peru. Very few of these opossums have been recorded, but it’s estimated that their populations are declining. Deforestation is their biggest threat.

You can only find Karimi’s fat-tailed mouse opossum (Thylamys karimii) in the Cerrado and Caatinga eco-regions of Brazil, in the central and northeast parts of the country. Like other fat-tailed opossums, this one stores fat in its tail to use when food is scarce. They average 104mm long, excluding their tails, with white bellies, darker brown-grey fur and large, dark eyes.

These opossums live in a range of habitats, from grasslands to dry forest, but despite that range, habitat loss is causing their populations to decline. 

On the western slopes of the Andes, from Ecuador to Colombia, lives the little woolly mouse opossum (Marmosa phaea). It has dark eyes and brown fur and a long, slender nose. Its habitat is shrinking, as forests give way to agriculture and development. And as the habitat shrinks, populations of this opossum shrink, as well. 

Reig’s opossum (Monodelphis reigi) comes from BolĂ­var State, Venezuela, although it might exist in Guyana, as well. Only one specimen has ever been recorded. Because it’s so little known, scientists also aren’t sure how stable its populations are. The habitat is deeply fragmented, however, owing to construction and mining activities. The one recorded specimen came from Canaima National Park, so it’s hoped that this protection will benefit the species.

Critically Endangered

Handley’s slender mouse opossum (Marmosops handleyi) is found in only one place on earth: the rainforests of Antioquia, Colombia, where its populations are declining. Only two have ever been captured, in fragmented forest regions, and the forest in this area is rapidly being cut down to make way for development and agricultural land. This little opossum reaches 104-122mm in length, with mousey grey fur and a long, pinkish nose.

7 Neat Facts About Opossums

opossum in tree - are opossums endangered

Opossums get a bad reputation, sometimes, because they can look fierce and frightening. And when we don’t like an animal, that can lead humans to care less about what happens to them, even to the point where an animal population can become endangered. 

So to help change some hearts and minds about these creatures, we offer you some interesting facts about the common opossum:

They can play dead for up to 6 hours. When opossums “play possum,” as this behaviour is called, they involuntarily go catatonic, falling over, going stiff and foaming at the mouth with a gross-smelling liquid.

They’re smart. In lab tests, they outperform rats during maze puzzles and score better at learning than dogs. 

Opossums have some unique anatomical features. The National Wildlife Federation explains that females “have two sets of reproductive organs,” while male opossums have forked penises. 

Opossums have the shortest pregnancies of all mammals. They last an average of 13 days. Once babies are born, most opossum mothers carry them around in a pouch, like a kangaroo.

The Opossum Society of the United States tells us that when babies are born, they’re so small that you could fit 20 of them into a teaspoon.

Aside from having the shortest pregnancies of all mammals, opossums also have some of the shortest lifespans for mammals their size—about 1-2 years, according to the Opossum Society.

Oh, and they’re immune to many poisons, including beestings and scorpion stings, botulism and rattlesnake bites. Which is helpful, because they eat rattlesnakes.

Written by Anne Elliott