Geographical Range Australia, including Tasmania
Habitat From desert to grassland to forests to alpine habitats
Scientific Name Tachyglossus aculeatus
Conservation Status Common

Mammals That Lay Eggs?

This animal may have sharp spines, but it isn't a porcupine! It's one of two types of primitive egg-laying mammals, or monotremes. (The other is the duck-billed platypus.)

A Living Pincushion

The first thing you probably notice about an echidna (pronounced ee-kid'-na) are the spines that cover most of its body, except for its face and belly. The animal also has short fur in between its spines, as well as on its underside. The spines are a great protection against predators. When the echidna wedges itself in a hole or rolls up in a ball, it's almost impossible to attack this living pincushion!

The echidna's long front claws might look scary too, but they're more useful in digging than in protection.

There are two types of echidnas, short-beaked and long-beaked. The short-beaked is much smaller than its cousin, weighing from five to 15 lbs., with a length of 12 to 18 inches. (As the name implies, the long-beaked echidna has a longer, more downward curving beak. Its spines are shorter and they may be hidden by its longer fur.)

Slurping its Supper

With its long snout and powerful front legs, the body of an echidna seems tailor-made for slurping up its favorite foods: ants and termites. The animal also eats other insects and worms.

An echidna uses its strong front claws and long stiff nose to plow through forest litter, break open ant- and termite-mounds, and overturn hollow logs. Once it finds tasty bugs, it sucks them up with its long, sticky tongue. Because an echidna has no teeth, it grinds its food between the top of its mouth and the horny back of the tongue.

Though they will usually take a daily meal, echidnas have been known to go for at least a month without eating.

From Egg to Adult

Echidnas and other monotremes are best known for the way their babies are born -- they hatch from eggs! But how do the babies begin?

Breeding season in the wild is usually July and August (in captivity in the Northern Hemisphere, echidnas breed from December through February). Males begin the mating process: several of them engage in so-called 'train' behavior, in which they follow closely behind one female. Then the largest male will usually breed her several times during a one- or two-day mating period.

A breeding female echidna develops a temporary pouch on her abdomen. When she deposits her single egg, she lays it directly into this pouch. The egg has a tan, leather-like shell. The egg incubates (develops) in the mother's pouch for 10 to11 days before the baby hatches.

When a baby echidna hatches, it is less than half-an-inch long, completely naked and helpless. It remains in the pouch for six to eight weeks, sucking the thick, yellowish milk known as "pap" from the mother's mammary glands. Since echidna pouches aren't as fully developed as the pouches of marsupial mammals (like kangaroos and koalas), the baby echidna has to hold on to its mother's pouch hairs to stay in place!

Slowly, the baby's fur and spines begin to emerge through its pink skin. By the time the youngster is about 55 days old, it begins to feel "prickly" -- no wonder the mother ejects it from her pouch! She then deposits the baby in a nursery burrow she has dug, where it remains until it is weaned. Every few days, the mother returns to suckle the young. The baby is weaned at five months, when it emerges from the burrow and begins life on its own.

I Want to be Alone

Though their sharp spines may make them look scary, echidnas are shy, retiring animals. They like to live alone; in fact, they don't show much social behavior. Echidnas don't engage in courtship, aggression, or maternal behaviors like many other mammals. One scientist says their behavior is not only simpler than that of most mammals, but than that of many lizards!

Echidnas spend the day holed up in quiet shelters, which can range from shallow burrows to hollow logs to cavities under rocks or roots. Then they emerge late in the afternoon or at night to feed, depending on the daily temperatures and the time of year.

When disturbed or alarmed, they have a variety of options to seek safety. Because they're strong diggers, they can burrow underground with amazing speed. They can also use their spines and feet to wedge themselves into crevices so that predators can't dislodge them. If all else fails, echidnas can roll up in a ball, leaving an attacker with a spiny dilemma.

No Worries, Mate!

Short-beaked echidnas are common throughout Australia, and their future seems rosy. Not so, however, for their close cousins in Papua New Guinea -- long-beaked echidnas. These animals are endangered because of habitat loss and hunting. The Saint Louis Zoo is working with others to save this animal before it becomes extinct in the wild (see side story).

Fun Facts

  • Short-beaked echidnas are popular with zoos, since they are the only representative of egg-laying mammals established in captivity.
  • These echidnas can live for more than 50 years in captivity.
  • Echidnas have very poor eyesight, but they more than make up for this with excellent hearing.

Class: Mammalia
Order: Monotremata
Family: Tachyglossidae