Australia is home to nocturnal marsupials commonly known as possums. These animals are distinct from the North American opossum, despite the similar name. While both are marsupials, Australian possums and North American opossums belong to different evolutionary lineages.
The Australian Possum Family
Australia has approximately 23 species of possums and gliders, varying widely in size, appearance, and adaptations. The Common Brushtail Possum and Common Ringtail Possum are most frequently encountered in urban and suburban areas. These, along with species like the Sugar Glider, are part of Australia’s rich wildlife.
The Common Brushtail Possum (Trichosurus vulpecula) is a medium-sized marsupial, comparable to a domestic cat, weighing 1.2 to 4.5 kilograms. Its fur color varies from silver-grey to brown, black, or golden, with lighter undersides. They have large, pointed ears and a bushy, prehensile tail, often black with a hairless patch underneath.
The Common Ringtail Possum (Pseudocheirus peregrinus) is smaller than the brushtail, weighing 0.55 to 1.1 kilograms, with a body length of 30–35 centimeters. They have grey-brown to reddish-brown fur, a pale cream-white underbelly, short rounded ears, and large eyes. A distinctive feature is their long, tapering, prehensile tail with a white tip, used for gripping and carrying nesting materials.
Sugar Gliders (Petaurus breviceps) are smaller, agile possums known for gliding. They have a patagium, a membrane of skin stretching from their wrists to their ankles, allowing them to glide significant distances between trees. These marsupials have soft, grey fur with a dark stripe down their back and a pale belly. They are highly social, often living in colonies.
Key Differences from North American Opossums
Despite similar names, Australian possums and North American opossums are distantly related, belonging to different marsupial orders. Australian possums are in the order Diprotodontia, which includes kangaroos and koalas, and specifically the suborder Phalangeriformes. North American opossums, such as the Virginia opossum, belong to the order Didelphimorphia. This taxonomic distinction indicates they diverged millions of years ago.
Physical differences are evident between the two groups. Australian possums have dense, soft fur, often with bushy tails. North American opossums, such as the Virginia opossum, have coarser, gray and white fur, and a more rat-like, largely hairless tail. Australian possums have furred ears, while many North American opossums have naked ears.
Their dental structures and foot morphology also differ. North American opossums have a dental formula with five upper and four lower incisors, and their hind feet have an opposable first toe without a claw. While some Australian possums also have opposable digits for climbing, their physical characteristics and adaptations are unique to their lineage.
Australian Possums in Their Environment
Australian possums are primarily nocturnal, foraging for food at dusk. This helps them avoid daytime predators and reduces resource competition. During the day, they rest in sheltered locations like tree hollows, dense foliage, or even house roofs in urban settings.
Their diet varies by species and available resources. Common Brushtail Possums are largely omnivorous, consuming eucalyptus leaves, flowers, fruits, seeds, and occasionally insects or small vertebrates. In urban areas, they adapt their diet to include garden produce and human food waste. Common Ringtail Possums are primarily herbivorous, feeding on eucalyptus leaves, other native vegetation, flowers, and fruits. Sugar Gliders have a diet rich in sweet substances like nectar, sap, and fruit, supplemented by insects.
Possums are arboreal, well-adapted for life in trees. They use their prehensile tails as a “fifth limb” for balance and grasping branches, with sharp claws and specialized feet aiding in climbing. Many species are solitary, but some, like the Common Ringtail Possum, live in communal nests called dreys, spherical structures made of sticks and leaves. They communicate through vocalizations and scent markings to establish territory.
Conservation and Coexistence
Australian possums face several threats, including habitat loss from urbanization and land clearing, road accidents, and predation by introduced species like domestic cats and foxes. Climate change, leading to more frequent bushfires and droughts, also impacts their habitats and food sources. Despite these challenges, many possum species, particularly the Common Brushtail and Common Ringtail, have adapted to urban environments.
Possums are protected by law in Australia, highlighting their ecological significance. They play a role in seed dispersal and help regulate certain plant populations. If possums reside in human dwellings, such as roof spaces, it is important to manage their presence humanely and legally.
This involves securing potential entry points and removing attractants like fallen fruit or uncovered garbage. Professional wildlife services can assist with humane relocation if necessary, as handling possums without proper training can stress the animal or lead to bites or scratches.
While generally shy and not aggressive, possums may defend themselves if threatened. The risk of disease transmission from Australian possums to humans is very low; however, they can carry parasites like fleas. Coexisting with these native marsupials involves understanding their behavior and taking preventative measures to minimize conflicts.