Echidnas are found on the Australian mainland, Tasmania and Papua New Guinea and are conspicuous for their spine-covered bodies and long pointed snouts. Their main food is termites and ants and these are obtained by means of a long sticky tongue. Their paws are adapted for burrowing, and when threatened an echidna can dig quickly and almost vertically into the soil. It may also use its spines and feet to wedge itself into a crevice or burrow, but if unable to find a refuge will curl itself into a spiky ball with the feet and snout protected underneath.
The echidna, unlike most other mammals, is somewhat venomous. On its ankles the male bears sharp curved spurs through which a poison can be injected into enemies. Echidnas together with the platypus, are the only egg-laying mammals and are grouped in the Order Monotremata.
Echidnas are small animals growing to about 45 cm in length. The body is covered with coarse brown hair which, on the back, develops into strong quills measuring up to 6 cm long.
The spines make it difficult for the animal to scratch its skin but the second digit of the hind-foot is very long and is used for grooming. The colour varies from light brown to black.
Having poor eyesight they depend on their acute sense of smell to locate their prey which is rapidly licked up by the long sticky tongue. The snout is long and beak-like and carries the two nostrils and a tiny mouth at the end.
The limbs have very strong claws well adapted for digging; when disturbed, the animal virtually sinks into the ground—not head-first like most burrowing mammals. Once partly buried it is almost impossible to dislodge. Curiously, the fore-feet of spiny anteaters are partly webbed although they are completely terrestrial.
Echidnas are found only in Australia and New Guinea, where they inhabit varied environments such as rainforests, scrublands and arid regions but are most numerous in rocky areas.
The echidna lives in dry, wooded, or grassy areas. It sleeps in a burrow during the day and comes out at night to hunt ants, termites, and other insects. With its strong spadelike claws the echidna rapidly digs up the ground or tears into termite nests. It pokes its slender snout into the nests, quickly extending its long sticky tongue to catch the insects.
During winter Echidnas spend most of their time asleep, but in warm weather they may be seen in the late afternoon scratching among stones and leaves and sniffing out ants and other small insects.
In New Guinea, and on Salawati, an island off the far west coast, there is also a long-beaked echidna (Zaglossus). This species is found only in the forests of the central and high mountain ranges. The beak of this species, which is curved, may be 12.5cm long compared with the 5cm beak of the Australian echidna.
Like its close relative the platypus, the echidna is an egg-laying mammal. The female, which mates once a year, digs herself into a burrow to lay her eggs. She curls up, and the loose skin of her abdomen folds over to form a pouch. She secretes a sticky substance, which flows into the pouch, and then lays one to three eggs, which roll into the pouch. The sticky substance hardens, gluing the pouch in shape and securing the eggs in it. After hatching, the young is suckled in the pouch and feed from milk glands on either side of the abdomen until it begins to develop spines when, not surprisingly, it is removed and placed in a den.
There are two genera of echidnas, Tachyglossus and Zaglossus. The Tasmanian echidna (T. setosus) and the Australian echidna (T. aculeatus) have five toes on a foot. The spiny anteater of New Guinea (Zaglossus) is larger than the Tasmanian and Australian echidnas and has only three toes on each foot.
The Angus & Robertson Concise Australian Encyclopaedia, Second Edition, 1986
Pears Cyclopaedia, Twenty-Ninth Edition, 1926.
Merit Students Encyclopedia, Volume 6, P.F. Collier Inc, 1979. Page 175.
Australian Encyclopedia, Collins Publishers, 1984. Page 428.
Concise Encyclopaedia of Australia and New Zealand, 1977, Bay Books. Page 146.