Echidnas

(Tachyglossidae), a family of oviparous mammals. There are two genera, consisting of the true, or shortbeaked, echidnas (Tachyglossus), with two species—the Australian (T. aculeatus) and Tasmanian (T. setosus) echidnas—and the New Guinea, or long-beaked, echidnas comprising three species. The best known is the Australian short-beaked echidna. The echidna’s body, attaining a length of 50 cm, is thickset, and its back is covered with spines. Its legs are short and thick, with strong claws adapted for digging. The rear legs have spurs, particularly well developed in males, which are connected with a poisonous gland by an internal duct. The tail is extremely short.

Echidnas possess a number of primitive characteristics: they lack teeth, and the female’s oviducts lead into a cloaca. Body temperature fluctuates between 22°C and 37°C, depending on the ambient temperature. In contrast to most mammals, which give birth to live young, the female echidna usually lays a single egg and carries it in a pouch on the abdomen. The developed offspring breaks the eggshell with an egg tooth, which then falls off. The young feeds by licking the thick excretion of the tubular milk glands. When the offspring begins to develop spines on its body (having attained a length of 8-9 cm), it leaves the mother’s pouch and hides in a small burrow dug by the mother. Echidnas live in thick underbrush, feeding on ants, termites, worms, and other invertebrates, which they extract with a long tongue covered with sticky saliva. The echidna is a nocturnal animal.