Nature^123
FIND OUT MORE. Feeding 98 • Reproduction 101 • Vertebrates 102
MONOTREMES
The small group of egg-laying mammals contains just five species -
the duck-billed platypus and four species of echidna. Monotremes are
found only in Australia and on the island of New Guinea.
These secretive, burrowing creatures are rarely seen.
2 SPINY ARMOUR
The echidna bristles with
defences against its enemies.
Male echidnas and
platypuses also have spurs
on their legs.CLAMBERING KOALA 3
Many marsupials are expert climbers. Koalas
feed exclusively on tough eucalyptus leaves. The
leaves contain little nourishment, so koalas save
energy by sleeping for up to 18 hours per day.WHAT DO MONOTREMES FEED ON?
Monotremes eat invertebrates, which they search for
at night. Echidnas, also known as spiny anteaters, feed
on termites and other insects. They slurp them up with
their long, sticky tongues. Platypuses hunt under
water, searching out worms, crustaceans, and insects
with their soft, sensitive beaks.
HOW MANY EGGS DO MONOTREMES LAY?
Platypuses and echidnas lay between one and three
soft-shelled eggs. Female echidnas incubate their eggs
in pouches on their abdomens. The platypus
curls around her eggs in her burrow.
When the eggs hatch, after about
10 days, the babies feed on milk
seeping from patches on the
mother’s abdomen. The young
become independent after four
or five months.
2 NEWBORN JOEY
A young kangaroo, or joey, is
born after just 4–5 weeks. Blind
and hairless, the tiny baby crawls
up its mother’s fur to her pouch
and clamps onto her nipple.4 JOEY IN THE POUCH
The fully developed joey begins
to leave its mother’s pouch at six
months old, but hops back in at
the first hint of danger. It becomes
independent when one year old.WHAT DO MARSUPIALS EAT?
Many marsupials are plant-eaters.
Kangaroos and wombats feed mostly
on grasses, while koalas eat leaves.
Some gliders feed on nectar from
flowers. Tasmanian devils are solitary
and nocturnal, preying on rabbits,
chickens, and other small animals.
Virginia opossums are omnivorous,
eating fruit, eggs, insects, and
other small creatures.Long snout used for probing
into termites’ nestsSTRANGE COMBINATION 3
The platypus has a duck-like beak,
a mole-like body, webbed feet,
and a beaver-like tail. When the
first, stuffed specimens reached
Europe in the late 1700s, people
thought they were fakes.MARSUPIALS
The group of marsupials includes kangaroos, wallabies, possums,
gliders, and wombats. All marsupials are born early and complete
their development in their mother’s pouch or clinging to her fur.WHERE DO MARSUPIALS LIVE?
Most marsupials live in Australia and surrounding
islands, but some are found in South America, and
one, the Virginia opossum, lives in North America.
Marsupials multiplied and evolved into all sorts of
species in Australia because there were no placental
mammals there to compete with them.mammals