Marsupials are mammals that give birth to underdeveloped embryos, which then climb from the birth canal into a pouch on the front of the mother's body. Once inside, the infant, sometimes called a joey, feeds and continues to grow by attaching itself to a nipple. While most marsupials are native to Australia and the surrounding islands, some are found in the Americas.
Kangaroos and Wallabies
Australia, Tasmania and New Guinea are home to more than 50 species of kangaroos and wallabies, known as macropods, due to the large feet of these marsupials. The largest, the red kangaroo of Australia's inland plains, can be up to six feet tall; gray kangaroos are smaller and found in woodlands. Wallabies, medium-sized marsupials, live in a variety of habitats, including shrubs, swamps and rocky cliffs. Ground-dwelling kangaroos and wallabies get around by hopping. There are also 14 species of arboreal kangaroos, two of which, the Bennett and Lumholtz varieties, occur in Australia. Kangaroos and wallabies are herbivores that eat a variety of grasses and other vegetation.
The gray-furred, tree-dwellers commonly referred to as koala bears are also marsupials. A koala's pouch faces backward, an adaptation that enabled its burrower ancestors to dig tunnels without getting dirt in their pouches. Found in eastern and southeastern Australia, koalas live in eucalyptus trees, the leaves of which comprise their entire diet. Koalas grow to be two to three feet long and weigh between nine and 29 pounds.
The wombat, which the National Geographic website describes as "pudgy," is a burrower marsupial with brown or gray fur. Like a koala, a wombat's pouch faces the legs to keep dirt out as the animal digs. Wombats are herbivores that feed on grasses, roots, tubers and even tree bark. There are three species: the common wombat, northern hairy-nosed wombat and southern hairy-nosed wombat. Hairy-nosed wombats have larger ears and softer fur than common wombats.
Named by European settlers for the fierce temper they display when threatened or fighting for food, today the nocturnal Tasmanian devil occurs only on the island of Tasmania. It has black or dark brown fur, grows up to 30 inches in length and can weigh up to 26 pounds. Females give birth to 20 to 30 young at a time, but only have enough nipples inside their pouches to nourish four. Tasmanian devils, the largest carnivorous marsupial, consume fish, insects, snakes, birds and carrion.
Possums, which are tree-dwellers, are the most widespread marsupial. Like Tasmanian devils, possums give birth to as many as 20 offspring, but only a few survive. There are 13 species of possums in Australia. North America is home to one species, the Virginia opossum, known to "play dead" when threatened by a predator. The yapok, or water opossum, one of multiple possum species in South America, is carnivorous and an able swimmer.
Australia has six species of gliders -- relatives of the possum that have a membrane between the front and rear limbs that allow them to momentarily float through the air. Among them is the tiny feathertail glider, which gets its name from its feather-like, prehensile tail, and the better known sugar glider. Gliders are active at night and live in trees in Australia's woodlands and forests. They subsist on nectar, pollen, sap, leaves and insects.
- San Diego Zoo's Animal Bytes: Marsupials
- National Aquarium: Australian Animals - Marsupials PDF
- San Diego Zoo's Animal Bytes: Koalas
- San Diego Zoo's Animal Bytes: Kangaroo and Wallaby
- San Diego Zoo's Animal Bytes: Wombat
- National Geographic: Tasmanian Devils
- National Geographic: Wallaby
- Australia Zoo: Our Animals - Mammals - Possums and Gliders
- Philadelphia Zoo: Feathertail glider
- Wildlife Queensland: Gliders
- Tom Brakefield/Stockbyte/Getty Images