Tachyglossus aculeatus
The echidna is common throughout most of temperate Australia (where it is the most widespread native mammal), including Tasmania, and in lowland New Guinea. It is also known as the Spiny Anteater because of its diet of ants and termites.
Like the Platypus it has a low body temperature — between 30 and 32 °C — but unlike the Platypus, its the body temperature may fall as low as 5 °C. It does not pant or sweat and in autumn and winter it shows periods of deep hibernation.
Numerous physiological adaptations aid the lifestyle of the short-beaked echidna. Because the animal burrows, it can tolerate very high levels of carbon dioxide in inspired air, and will voluntarily remain in situations where carbon dioxide concentrations are high. Its ear is sensitive to low-frequency sound, which may be ideal for detecting sounds emitted by termites and ants underground. Its leathery snout is covered in mechano- and thermoreceptors, which provide information about the surrounding environment. The short-beaked echidna has a well-developed olfactory system, which may be used to detect mates and prey.
If disturbed, echidnas will usually lower the head, and with vigorous digging, sink rapidly into the ground leaving only the spines exposed. On hard surfaces they will curl into a ball — presenting defensive spines in every direction. They are also capable of wedging tightly into crevices or logs by extending their spines and limbs.
Surprisingly, echidnas are good swimmers, paddling about with only the snout and a few spines showing. They have been seen to cross wide beaches to swim and groom themselves in the sea.
Two weeks after mating, a single rubbery-skinned egg is laid directly into a small backward-facing pouch which has developed in the female. After 10 days the egg hatches and the young remains in the pouch. When a baby echidna hatches, it is less than half-an-inch long, completely naked and helpless. As echidnas lack nipples, the mammary glands secrete milk through two patches on the skin from which the young suckle. 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! Juveniles are eventually ejected from the pouch at around 2-3 months of age due to the continuing growth of their spines.
The diet of echidnas is largely made up of ants and termites, although they will eat other invertebrates, especially grubs, larvae and worms. The strong forepaws are used to open up the ant or termite nest and the echidna then probes the nest with its sensitive snout. Any insects in the nest are caught on the echidnas rapidly moving 15 cm tongue which is covered with a layer of sticky mucous, hence the genus name Tachyglossus, meaning “fast tongue”.
The echidna is common and widespread. They are less affected by the clearing of land as much as many other native animals as they can live anywhere that there is a supply of ants. Despite their covering of spines they do have natural predators such as eagles and Tasmanian devils which even eat the spines.
The picture was taken at the Scienceworks museum in Melbourne, in January 2005.
Family Tachyglossidae
Order Monotremata
Subclass Prototheria
Class Mammalia
Subphylum Vertebrata
Phylum Chordata
Kingdom Animalia
Life on Earth
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