The Echidna is an Egg Laying Mammal

The two species of Echidna are two of only three egg laying mammals known. The egg laying mammals are members of the Monotremes, an order of mammals different from either the placentals or the marsupials.

The Echidna is Australia’s most successful mammal.

Echidna fossils indicate that this animal was around 120 million years ago. This is a long time. Tyrannosaurus Rex fossils indicate that this animal originated about 68 million years ago. That is, the Echidna developed about 52 million years before the Tyrannosaurus. The Echidna then survived whatever killed the dinosaurs and has lived another 65 million years since.

This does not imply that the Echidna has not evolved in this time, but suggests that it has been a successful basic shape through vastly changing conditions. Echidnas live up to 45 years. They can breed at about 6 years old. Studies on Kangaroo Island suggest that they only breed every three to seven years, so the Echidna is not a prolific breeder.

Breeding

The shape of the Echidna makes the usual mammal mating position impossible. The female lays down a scent trail and each male that finds it follows the female. There can be as many as ten males following the female. When she is finally ready to mate, she digs the front part of her body into the ground. All the males try to dig under her. If there is more than one male this results in a doe nut shaped hole. The males try to push each other out of the hole, pushing nose to nose. When only one is left, he will have dug slightly under the female and he turns on his side and puts his cloaca into contact with the female’s cloaca. The male can then extend his four headed penis and complete the mating. The mating is not completely face to face, but is more like this position than the usual mammal mating position.

If only one male is present, the hole for mating will be a straight trench.

The female lays her egg about 22 weeks after mating. It is not known definitely how the female gets the egg into its pouch, but it seems most likely that the female bends enough to lay directly into its pouch. The pouch of the Echidna is just an arrangement of skin folds. The male has a “Pouch” as well, and it is difficult to determine the sex of an Echidna.

A baby Echidna is called a Puggle. The Puggle may only weigh about 3 grams (a tenth of an ounce) straight after hatching but can increase to 180 grams (6 ounces) after 60 days.

Bringing Up the Puggle

The baby Echidna lives in its mother’s pouch for about seven weeks, feeding on the milk from the two milk patches in the pouch and growing very fast. When the Puggle’s spines start to harden the mother Echidna transfers the Puggle to a nursery burrow. She returns every five to ten days to feed her Puggle. After about five months the mother stops going back and the young Echidna is by itself. The Echidna is unusual among the mammals in not appearing to instruct its young.

Food

The Echidna’s main food is termites. This insect is very common and widespread in Australia. Echidnas will also eat ants and other invertebrates including worms and grubs.

Predators

There were not many native predators of the echidna. Wedge-tailed Eagles will sometimes eat an Echidna, and Goannas can eat the Puggles while they are in the nursery burrow.

However there are several introduced predators of the Echidna. The first one was the Dingo. This was a domestic dog brought in by the aboriginal people of Australia many thousand years ago and went wild. More recently there have been other dogs, but worse than these are the cats and foxes. Some of these introduced predators have learned techniques for dealing with this prickly animal.

Echidnas are very fast diggers and on soft ground will escape their predators by digging. On hard ground the Echidna will roll up into a ball, wait and hope the predator will go away. The spines of the Echidna are not as fearsome as those of the porcupine, but still quite sharp. Humans should not handle an Echidna without suitable protection or knowledge. Puncture wounds from the spines can get infected. Also, Echidnas should not be relocated without good reason. The animal could be a female that is feeding a Puggle in a nursery burrow. Moving the adult to another area could result in the death by slow starvation of the baby.

As well as this, the mother may try to get back to its baby and be killed on the road.

Habitat

Echidnas live in a very wide variety of places such as the dry interior of Australia, the tropical rain forests and even the cities. The basic requirement of Echidnas is termites.

Fire

In Australia there are sometimes devastating bush fires that kill thousands of animals. The Echidna cannot run fast. When there is a fire they usually only succeed in getting about a metre (3 feet), but they do this in the right direction. They dig straight down and usually survive even a very bad fire.

Brain

The Echidna’s brain’s prefrontal lobe is larger in relation to the animal’s size than any other animal, including human beings.

Types of Echidna.

There are two species of Echidna: the Short Beaked Echidna, Tachyglossus aculeatus which lives in Australia including Tasmania, and in the New Guinea lowlands, and the Long Beaked Echidna, Zaglossus bruijnithat lives in the New Guinea highlands.

There are five sub species of Short Beaked Echidna including the Tasmanian sub species which is bigger than the mainland ones and has fur longer than its spines.