Mammals: Marsupial

Range: North America, Central America, South America, Australia, and New Guinea Habitat: desert, savanna, chaparral, forest, rain forest, and urban areas

The spotted cuscus is an endangered marsupial from New Guinea.

Life in a backpack

Wouldn’t it be cool if you could be carried around in a backpack your entire childhood? You’d never have to worry about falling off of Mom’s back or getting caught by predators! Well, marsupials are the kinds of animals that can do this. They are known as the pouched mammals because the adult females have a marsupium, or pouch, usually on the outside of the body where the young (called joeys) are raised. It acts as a warm, safe place where the joeys grow.

Most adult female mammals give live birth outside of the body; during development inside of the mother, the baby is connected directly to the mother’s blood supply by a placenta. These are called placental mammals. Marsupials give live birth, too, but the embryo climbs its way from the birth canal up to the pouch. Once there, the embryo attaches to a nipple and doesn’t let go because it can’t! The nipple instantly swells in the embryo’s mouth so that it is only able to let go when it is more developed.

Tiny short-nosed rat-kangaroos, or bettongs, live in burrows in Australia’s arid scrubland.

So different yet
so similar!

Most people think of Australia when they think of marsupials because the most well-known of the marsupials, koalas and kangaroos, live there. But opossum species, which are also marsupials, are found in North, Central, and South America. Most marsupials have four small legs and feet, such as opossums and quolls, while kangaroos and wallabies have two large feet and two “arms.”

As mentioned, all marsupial females have a pouch, but the pouch of the Virginia opossum of North America and the wombat of Australia points backward toward the tail instead of forward toward the head. All marsupials are covered in hair and feed their young milk. They generally have good hearing and smell. Most walk on the ground or are good climbers, and one, the water opossum, or yapok Chironectes minimus, of South America, can swim! The numbat Myrmecobius fasciatus is the only marsupial that is active during the day—all others are nocturnal or crepuscular. Bandicoots, kangaroos, wallabies, and possums have two toes fused together, while all the others have separate toes.

The tiger quoll is a small carnivorous marsupial native to the rain forests of Australia and Tasmania. It is also called a spotted-tailed quoll or tiger cat.

What a mouthful!

So, what’s for dinner? Marsupials have different types of teeth, depending on what they eat, from bugs to other smaller mammals or birds to fruit and seeds to eucalyptus leaves. Bandicoots, Australian possums, and American opossums are omnivores. Wombats, kangaroos, and koalas are the herbivores. The rest are insectivores or carnivores. Marsupials usually have more incisor teeth than other mammals do: the Virginia opossum has 52 teeth altogether, the most teeth for any North American mammal!

So many places to make a home

Marsupials generally don’t live in areas that get snow, except for the mountain pygmy-possum Burramys parvus, which lives in the Australian Alps. Most Australian marsupials live in dry scrub or desert habitat, as that is mostly what covers that continent; in South America, they generally live in forests or tropical rain forests. Marsupials can live in any part of the forest habitat, from the trees to the forest floor where, like the wombat, they burrow underground.

Unlike cartoon opossums, the Virginia opossum doesn’t sleep hanging down from a branch by its tail but instead curls up in a cozy nest.

North America’s only marsupial

The Virginia opossum is the only marsupial found in North America, and its native habitat is moist forests, although it may also be found in your neighborhood. It is an important part of our environment, acting as a scavenger to clean up trash, fruit, and dead animals. If you spot one in your neighborhood at night, watch how it uses its dexterous tail and paws to get around, but for your own safety, don’t get too close: opossums can be fierce fighters! If it’s springtime, pay special attention—if the opossum happens to be a mother, you’ll see up to 13 babies hanging on to her back!

A Buergers’ tree kangaroo joey peeks out from the safety of its mother’s pouch.

Pouch life

Most marsupials are solitary during the year, except when it is breeding season. Generally, males and females will breed with different partners and then go their separate ways. Females raise their joeys on their own. Most females develop or have some type of pouch for their young. But don’t be fooled—not all marsupial pouches are as deep as a kangaroo’s pouch. Unlike the koala or kangaroo, most marsupial mothers give birth to several joeys at one time. Because of this, the pouch is shallow so that when the joeys are old enough, they can climb onto Mom’s back instead of creating a lot of weight for her to carry around in her pouch.

When the joeys are born, they are much more helpless and undeveloped at birth than placental mammal babies, and this is the reason for having the pouch. It protects the young, keeps them warm, and is the location where the joeys can get milk. Once the joeys have attached to a nipple to nurse, they grow and develop there for weeks to months, depending on the species. Once the joeys are large enough, they leave the pouch and hang on to their mother’s fur instead. Mom and offspring can stay together for up to a year in some species! Generally, when the youngsters are weaned and out of the pouch permanently, they leave their mother soon after.

Positive contributors

Marsupials are pollinators and seed distributors. They control pests by eating insects and vermin. Some make habitats for other underground animals by digging their burrows as well as loosening up the soil. The Virginia opossum helps to clean up the environment by eating carrion, rotting fruit, and other items we consider garbage. In fact, this animal is often found rummaging around in garbage cans!

Conservation status

These interesting critters often struggle to survive; kangaroos are currently hunted for food and hides. The greater bilby Macrotislagotis has decreased greatly over the years due to habitat loss from farming and introduced predators like feral cats and foxes. There are breeding programs for this species now, and they are being reintroduced into western Queensland in Australia to repopulate their lost numbers. The mountain pygmy-opossum numbers less than 2,000 in the wild, due to construction of roads, dams, and ski resorts in its mountainous habitat. The hairy-nosed wombat Lasiorhinus graffiti has about 70 individuals left in one of the national parks in Queensland, Australia. This wombat is at critical risk due to overhunting for its thick fur.

There are many more marsupials that are endangered or at critical risk, and several that have already gone extinct. Australia now uses various management practices to protect its marsupials. We also need to do our part to keep them around. Reducing your ecological footprint, recycling, being aware of the products you are buying and where they come from are all things you can do to help our pouched friends!