The echidna is best known for its amazing biology. Like the platypus, this unusual mammal lays eggs and suckles its young.
The echidna and platypus are the only members of a primitive group of mammals known as monotremes. Echidnas are toothless and feed almost exclusively on ants and termites. They expose termite galleries by breaking open nests with their strong forepaws or snout or by digging into soil. They then extract the termites, which adhere to their long, sticky tongues.
When disturbed, the echidna either curls into a spiny ball to protect its soft underside, or digs its belly into the soil, so that only the spines are exposed.
Long spines cover the body and fur is present between them. These slow-moving creatures have a bulbous forehead and a long snout to collect their food. Males have a spur on the ankle of the hind leg but, unlike that of the platypus, it is not venomous.
They are equipped with a long sticky tongue that extends perhaps 17 centimetres beyond the end of the snout.
Status and Distribution
Echidnas are widely distributed throughout the Australian continent and Tasmania. Although not commonly seen, they are not considered threatened.
They may be found in any place with a good supply of ants and termites. They live in a wide variety of habitats, from cold mountainous peaks to deserts. They deal with very cold weather by hibernating and avoid extreme heat by sheltering in burrows or other refuges.
Echidnas are usually solitary. However, during the breeding season between July and August they give off a strong smell that may help advertise their presence to the opposite sex.
During this time, several males may follow a single female in a “train” until she is ready to mate. About two weeks after mating occurs, a single soft-shelled egg is deposited directly into the pouch and hatches after 10 days.
Because the echidna does not have teats, the baby clings to specialised hairs within the pouch, where it suckles milk oozing from the mother’s mammary glands.
The initially tiny young has an incredible growth rate, increasing its body weight up to 500-fold in the first 45 days of life. Completely hairless when born, the young is covered with short spines by the time it leaves the pouch.
When it becomes too big and spiky to be carried about, the youngster will be placed in a burrow to which the mother returns every five or six days for suckling. Here it remains until about six months old.
Dingoes and goannas will occasionally eat echidnas. Their relative abundance on large, fox-free islands such as Kangaroo Island in South Australia suggests that the fox may be a significant predator.