Tachyglossus aculeatus
short-beaked echidna

Tachyglossus aculeatus inhabits most of Australia and many nearby islands including Tasmania and New Guinea.

Generally found in any areas where food items are plentiful, including forests, meadows, and Australian deserts. Echidnas have been found in high mountain area with snow cover for parts of the year. In arid areas, short-nosed echidnas tend to be noctural, while in higher elevations and more temperate areas, they are more diurnal.

The short-nosed echidna is the smaller of the two echidna species. Body length can be up to 530 mm, with a tail about 90 mm long. Spines, which are specialized hairs covering most of the body, are large, hollow and thin walled, measuring up to 60 mm in length. Spines are usually yellow with black tips, but can be entirely yellow. Underneath the spines, short-nosed echidnas are covered with dark brown or black body hair, although in one subspecies, the hair covers the spines almost completely. The head is small and often has the appearance of having no neck. The tail is short, stubby, and naked underneath. The snout is long and slender and about half the head length. The feet have five digits with flat claws used for digging. Male echidnas have a hollow spur on the hindfoot which is hollow and lacking in venom.

Short-nosed echidnas are solitary throughout most of the year except when breeding in July and August. It is common during the breeding season, however, to find groups of males walking in lines behind a single lead female. Males will often follow females for a few days until shes ready to mate. When the female is ready, she attaches her hind legs to a tree, and the males circle around her, often forming a doughnut-shaped trench in the dirt. One males finally gets to mate with the female, although how this male is selected is unclear. Echidnas do not seem to be territorial--home ranges (about 800 m in diameter) often overlap.

The primary foods of the short-nosed echidna are ants and termites. The snout is used to break open hollow logs and plow up forest litter, while the sticky tongue is used to catch the ants and termites. Horny spines on the upper side of the base of the tongue and palatal spines grind the food. Occasionally the strong claws are used to dig into termite and ant mounds, usually when the large proteinaceous queens are near the surface.

Echidnas are susceptible to a wide variety of diseases, but it is unlikely that any of these affect humans.

Although monotremes are an evolutionary novelty, echidnas are not rare in many parts of their ranges.

To avoid predation, echidnas often burrow directly down in soil, leaving only the spines protruding, while their claws grasp tightly to the substrate underneath. This makes an effective phalanx of spines to deter most any predator. Echidnas are also characterized by a body temperature which is lower than that of most mammals. In cold climates they enter hibernation or torpor to survive.