Echidna

Echidnas are small, spiny mammals native to Australia and New Guinea. Along with the platypus, they belong to the monotreme lineage, a primitive group of egg-laying mammals. There are four living species: the short-beaked echidna (Tachyglossus aculeatus) and three long-beaked echidnas in the genus Zaglossus (bartoni, bruijni, and attenboroughi).

They inhabit a variety of environments, from deserts to forests, but are primarily terrestrial and solitary. Echidnas have a coat of coarse fur with protective spines. Their long, slender snout functions as both nose and mouth and houses electroreceptors that help locate prey. They lack teeth and use a sticky tongue to capture ants and termites. Powerful forelimbs with strong claws enable them to dig for food and shelter.

Reproduction is distinctive: echidnas lay eggs. The female deposits a single egg, which hatches after about 10 days in a temporary abdominal pouch. The tiny puggle then remains near the mammary region, feeding on milk secreted by the mother. Unlike most mammals, echidnas have no nipples; milk is secreted from mammary glands and absorbed through the skin and fur of the young.

Echidnas have a low, variable body temperature and can enter torpor in cold or resource-poor conditions. They are mostly nocturnal or crepuscular and feed on ants, termites, and other invertebrates.

Conservation status varies by species. The short-beaked echidna has a broad distribution and is not considered highly endangered, while some long-beaked species face habitat loss and population decline.