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Although to some extent filling a niche in the landscape similar to South America’s ‘spiny anteaters’ and porcupines and hedgehogs that are widely dispersed across the world, echidnas come from a very different ancestry and are found only in Australia and Papua New Guinea. All Australian echidnas are a short-beaked species also known as Tachyglossus aculeatus (Tachyglossus meaning fast tongue and aculeatus meaning spine).
Along with their close relative, the platypus, echidnas are some of the oldest living creatures, having evolved between 20 million and 50 million years ago. The platypus and echidna are the only mammals (known as monotremes) that lay eggs and suckle their young. Their egg is laid into a backward-facing pouch that develops only during breeding. Within about 10 days, the tiny, hairless puggle, about the size of a jellybean, emerge. Female echidnas don’t have nipples so the puggles suckle from pores on the mother’s abdomen. By the time they are a few weeks old, the young echidnas have grown hair and spines. They leave their mother’s pouch and are placed in a shallow ‘burrow’ while their mother goes off to gather food. When about six months old, the young are ready to leave the nursery ‘burrow’ and live independently, often seen exploring their surroundings.
Their ‘beak’, which is really a long nose equipped with electro-sensors that detect movement as well as being sensitive to smell, plays an important part in seeking their food (mainly ants and termites). Once located, food is gathered up in their fast-moving sticky tongue, which is up to 15cm long. Lacking teeth, they grind their food between their tongue and hard little plates on the floor of their small mouth. Kept in captivity, they need some fine soil added to their food to aid digestion. Sensitive to noise, their ears are slits on the side of their head, often hidden under their hair and spines. Their spines are a modified form of hair strengthened with keratin, like our fingernails. Their main defences are to roll into a ball with spines erect, or to quickly dig into the ground.
In some ways echidnas are part way between warm-blooded mammals (and humans) and reptiles. The normal body temperature in echidnas and platypus is around 32°C (lower than most mammals) and is less well maintained in both hot and cold conditions. In cold conditions, and when heavily stressed, they enter a state of torpor - a ‘hibernation’ in which their metabolism slows down and temperature drops, from which they can emerge more quickly than other animals that hibernate.
They don’t sweat, so when too hot they’ll flop in a puddle or even go for a swim. Their hind limbs face backwards like those of lizards – better for digging. This adds to their ‘waddling’ gait, which is part of their novel appearance, but doesn’t mean they can’t get up some speed when necessary. During mating season (usually June to September) echidnas form ‘trains’ in which a line of males pursues a single female until one male prevails when the female is ready to mate. Although the average life-span of an echidna is reported to be about 14-16 years, some echidnas in captivity have lived as long as 40-50 years.
Want to see these fascinating creatures in person? Plan your trip to North Head Sanctuary.
Article written by North Head Sanctuary Foundation Founding President, Judy Lambert.
