Echidnas, together with the Platypus, are the world’s only monotremes, or egg-laying mammals.
Adult echidnas vary in size, from 35 to 53cm. Males weigh about 6 kilograms, while females weigh about 4.5 kilograms.
The short, stout limbs of an echidna are well-suited for scratching and digging in the soil. The front feet have five flattened claws which are used to dig forest litter, burrow, and tear open logs and termite mounds. The hind feet point backwards, and help to push soil away when the animal is burrowing. Two of the claws on each back foot are used for grooming. An echidna’s tail is short, stubby and hairless underneath.
July and August is breeding time for Echidnas, females will be carrying either an egg or a very small echidna in her pouch, so please check if you should see an Echidna on the road hit by a car, especially in the cooler months.
The soft-shelled egg is laid sometime between 10 and 36 days after mating. The female lays her egg by lying on her back, rolling it down her stomach and enveloping straight into her “pouch”. Echidnas do not actually have a permanent pouch; instead they have contracting muscles in their abdomens, which forms a pouch-like fold. As both male and female echidnas can form a pouch in this way, it makes the sexes indistinguishable.
After 10.5 days the young echidna, which is called a Puggle, taps on the inside of the egg with what is called an egg tooth to break the soft shell, this is the only tooth the echidna has, and it drops off 1-2 days after hatching. The Puggle stays in the pouch for a further 50 days until it starts to develop its spines, at which time mum will have dug a nursery burrow in which she will leave the Puggle. She will return every 5 to 6 days to feed the Puggle through a series of mammary pores on her stomach. Milk is secreted through these pores, and as with Kangaroos and Possums the milk changes according to the growth stage of the young. How clever is that? The young Echidna is independent at approximately 10 months old.
It is thought from previous studies that they do not breed till at least 5 years old, and we do not know the average life span of Echidnas, they have survived for over 50 years in captivity. What we do know is that their brain capacity is large, thus intelligent and they have incredible memory capabilities.
Body temperature is lower than most mammals; they share this low body temperature with the Platypus being 33 degrees as they are the only other species of Monotremes in Australia. They are excellent swimmers having spines that are hollow thus helping with flotation, and in summer will cool themselves by swimming or going underground in hollows or burrows. The spines are actually tough hollow hair follicles, the echidna also has fur between the spines, and in Tasmania the fur can be so long that it covers the spines.
If you see a train of Echidnas, with as many as 2 – 10 walking in a line, the female will be the largest at the front, with the males following along behind, according to size. The female may lead the males around like this for up to 6 weeks and males may lose up to a quarter of their body size. The males are, of course, hoping to mate with the female.
Echidnas do not only eat ants and termites, they also eat small invertebrates, worms and beetles. Their tongues are up to 17 cm long and covered in sticky saliva allowing the ants or beetles to stick to it, the tongue is then drawn back into the mouth, where the food is masticated between a horned pad at the back of the tongue and the palate. Adult weight varies from 2-7 kg.
Echidnas did not have many predators before white man arrived in Australia, but since our arrival predators now include dogs, and of course many succumb to our motor vehicles. It is a fairly slow moving animal, so when crossing the road it cannot readily get out of the way.