Possums are a suborder of 70 tree-living marsupial species native to Australia and the Indonesian islands of New Guinea and Sulawesi. While their names are similar and both are marsupials, possums and opossums are different creatures. Opossum typically refers to the Virginia opossum and its cousins in the genus Didelphis, all of which live in North and South America.
Both of the English words possum and opossum come from aposoum, which means “white animal” in Powhatan, a Native American language.
Kinds of possums
Brushtail possums are the most widespread marsupial in Australia and perhaps the most well-known possums. As their name suggests, brushtails have long, thick tails with a prehensile tip and a furless patch on the underside, both of which help them hang onto tree branches.
Unlike many other possum species, these solitary, nocturnal creatures are highly adapted to living near humans, even in urban areas such as Sydney. And like koalas, they have evolved the ability to feed on plants that would be poisonous for other animals. Possums may also prey on insects, small invertebrates, and eggs.
Another group of possums is the ringtails, which reside in communal nests called dreys. Found in tree branches and hollows, dreys often contain an adult female and male, as well as two sets of twins—one that is still nursing and another that is slightly older, but still dependent on the adults.
Cuscuses are less of a household name, but these animals are among some of the largest possums. For instance, the Sulawesi bear cuscus (Ailurops ursinus), named for its coat of thick, dark fur, can weigh up to 22 pounds.
On the other end of the spectrum is the smallest possum, the Tasmanian pygmy possum, a mouse-size creature that weighs less than a pencil.
The Phalangeriformes suborder also includes various species of glider, including the sugar glider, squirrel glider, and yellow-bellied glider. These curious marsupials have evolved flaps of skin between their arms and legs, called patagia, that allow them to launch themselves out of the canopy and soar to tree branches below.
One species, the feathertail glider, can “fly” up to 65 feet.
Mating and reproduction
Mating systems among the Phalangeriformes vary widely. For instance, the rock-haunting possums from tropical Australia appear to choose just one mate, which scientists call monogamy. Some gliders take multiple mates, which is called polygamy, while others are monogamous, and still more are variants in between. One study found that mountain brushtail possums will change their mating system depending on how much food is available.
Like all marsupials, possums have pouches and give birth to live young. These newborns are no bigger than honeybees and are typically blind and deaf.
To complete their development, young possums must crawl from the birth canal into their mother’s pouch, where they will compete for a teat. Milk is critical to the babies’ growth, which means that any young that cannot find and latch onto a nipple will perish. The lips of baby possums and other marsupials will actually fuse shut around the teat, ensuring that they are not easily separated from the lifeline between mother and offspring.
The amount of time varies for how long each species will spend drinking their mother’s milk, but after this period, possums will usually stay with their mother for a while. Even after they have weaned, the young of many marsupial species will still duck into the female’s pouch to stay warm and safe from predators.
While some species, like the common brushtail possum, are doing well, many possum species are in danger of extinction. Thanks to fires, logging, and climate change, the fairy possum, or Leadbeater’s possum, is considered critically endangered. Likewise, the mahogany glider is listed as endangered due to the rapid rate at which its habitat is being cleared for agriculture, livestock, and timber. Many of the same threats imperil the critically endangered western ringtail possum.
Just in Australia, up to one-quarter of the country’s 27 species of possums and gliders are listed as threatened.