Spiny ant-eaters, or to give them their formal name, echidnas, are monotremes. They are egg laying mammals, so they are quite different! Their young are called puggles. Echidnas and platypuses are the only egg laying mammals. In the wild they live to an average of about 14 – 16 years..
They like to live alone, mostly in Australia and New Guinea. There are only four remaining species of echidnas. Although some of them eat ants and termites they are not closely related to the American hedgehogs. They are pretty adaptable, tough creatures.
Echidnas don’t like extreme temperatures, so they prefer areas with dense bushland, which provide them with plenty of cover and access to plenty of food sources. If they are in open grasslands they will forage for food, and often dig burrows, both for looking for food, and for shelter. They will shelter from harsh weather in caves and crevices. They will even use burrows that other animals such as rabbits and wombats, have made. Scrublands can also offer hiding spots and food sources. Their strong sense of smell is very helpful in finding food.
Echidnas live a fairly long time for their size. The longest in captivity is 50 years, and in the wild the longest recorded is about 45 years. This is probably due to the relatively low metabolic rate which gives them good stress resistance.
The short-beaked echidna, which lives in a drier environment, has no more than 400 electro-receptors at the tip of its snout. This compares to the long beaked echidna, which has about 2 000. As a comparison, the platypus has about 40 000 electro-receptors on its bill.
A video of an echidna hunting and feeding.
An echidna hunting and feeding
Video courtesy of and copyright Adrian Prins.
Echidnas have a strong body, about 2 kilograms to 10 kilograms in weight, and about between 35 and 70 centimetres in length. They are covered all over with coarse hair and spines – except for underneath, which has a soft fur. The coarse hair and spines is made up of keratin, the same stuff that makes up the fur / hair / nails / claws / horn sheaths in animals.
Echidnas have short, strong limbs, with powerful claws. They are very strong diggers, and can tear apart soft logs to find earthworms, termites, and ants, which are their main food. They have long sticky tongues to actually catch them. They have ears, which are just slits under the spines in the side of their heads.
They are very good swimmers, swimming with their snout out of the water. Their body temperature is 33C, which is the second lowest among mammals, after the platypus.
Echidnas are myrmecophagous which means that they eat mainly ants and termites. Most of their energy comes from eating them, and especially their young, their eggs and larvae. Favourite places where they hunt these insects are mounds, rotten logs, and under bark. They need to get into their food quickly, and can eat around 200 grams of insects in around ten minutes.
Echidna reproduction is interesting. The male echidna has a four headed penis, two of which shut down and stay the same size during mating. The other two release semen into the female’s reproductive tract, which has two branches. Each time the male mates it uses the opposite penis heads to the last time.
The female lays a single leathery egg about 1.4 centimetres long, about 22 days after mating. About 10 days later the baby echidna is born, by using an ‘egg-tooth’ to open the leathery egg shell. It then sucks milk from two milk patches on its mother for the next 45 to 55 days. Then it begins to develop spines, and the mother digs a nursery burrow for it. The mother returns every five days to suckle the puggle for seven months. Puggles will stay longer, up to a year, before leaving.
Echidnas are timid. Their response to being attacked is to try to bury themselves and curl up into a ball. Their strong front arms allow them to dig in and hold fast against predators trying to pull them out. Dogs, feral cats, foxes, goannas are all predators. So are snakes who slither into burrows to eat the young puggles.
Echidnas are efficient swimmers. They have streamlined bodies which move through the water easily, powerful, well shaped fore-legs giving good power, and hind-legs pointing backwards to act as steering rudders.
In Australia the echidna is seen by native peoples as prized food. The Kunwinjku people of West Arnhem Land regard it as prized food and good medicine. They hunt it at night, gut it, and fill it with hot stones and mandak leaves.
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