ADAPTATIONS FOR THIS DIET
Echidnas have an extremely specialized diet, which has probably helped to make them so successful. No other mammal in Australia eats ants and termites, so they have no competition for food. The echidna’s body is highly adapted for this diet.
Echidnas have short muscular legs, with very long forefeet and very long sharp claws. These are used for burrowing into ant nests and termite mounds, and for turning over leaf litter and digging into rotten logs.
The mouth and nose are elongated to form a tubular snout. The tongue is very long, and can extend to about 18 cm (7 in) beyond the snout! It is covered with large amounts of very thick, sticky saliva. Ants and termites stick to the tongue as it pokes into every corner of the nest.
The tip of the tongue can even bend into a U-shape, so it can reach around corners into all the narrow galleries of the termite mound or ant nest.
The tongue moves extremely rapidly in and out of the mouth; in fact, the scientific name‘Tachyglossus’ means ‘fast tongue’. An echidna can ingest 200 gm of ants (nearly half a pound) in 10 minutes!
The echidna will also trap ants by lying on top of an ant mound and sticking out its tongue. As the ants walk onto the tongue, they are trapped by the sticky saliva.
The tongue is drawn back into the mouth, and the insects are crushed between a horny pad at the back of the tongue, and a similar hard surface on the palate.
UNUSUAL BREEDING BEHAVIOUR
Echidnas are normally solitary animals, so they need a way to attract other animals during the breeding season.
In July and August both males and females give off a pungent smell. This is easily detected by the sensitive nose.
Males will now start to follow a female, forming a ‘train’ of up to 11 animals. This train can last for up to 6 weeks, with the male sometimes nudging the tail or side of the female with his nose. Males will sometimes leave one train and join another. During this time the animals remain together while eating and resting.
Eventually the female signals her readiness to mate. She stops and partially digs her front legs and head into the ground near the base of a tree. The male echidnas that have been following her then start digging a trench beside her, jostling each other and digging around the bush until they have dug themselves into a doughnut-shaped rut.
The males begin pushing at each other with their heads until all but one has been shoved out of the rut. This male then turns on his side to the female, and mating occurs.
GIVING BIRTH AND RAISING THE YOUNG
About 22 days after mating, the female lays a single egg into a simple pouch– really just a thickened fold of skin– on her abdomen. The egg has a leathery shell and a large yolk, similar to reptile eggs.
About 10 days later, the embryo tears open the shell with its single egg tooth.
The baby echidna is called a ‘puggle’. It is only 1.5 cm long (0.6 in), about the size of a jellybean.
The front legs have tiny claws which cling to the hairs in the mother’s pouch. The female has no teats, but secretes milk directly onto two circular ‘milk patches’ called aerola. The young puggle sucks milk from these two patches.
The puggle grows extremely fast. In just 2 months it will have increased its body weight 60-fold, from 3 gm at birth ( 0.12 oz) to 180 gm (6.5 oz). At about 7 weeks of age it has started to grow spines, and is too prickly to be carried about.
At this stage it looks like a spiky black water balloon.
The mother puts the puggle into a nursery burrow, returning only every 5 or 6 days to allow it to feed on her milk secretions. This seems like a long time between meals, but during this single feeding, the puggle can drink up to 40% of its body weight!
At about 6 months of age the puggle will start to emerge from the burrow. When the young echidna is about 7 months of age, the mother will simply abandon it to forage on its own.
Females give birth only once every three to five years, but echidnas can live for up to 50 years.
DEFENCE AGAINST PREDATORS
Very young echidnas may be eaten by dingos, goannas, snakes and cats.
Adult echidnas are occasionally taken by dingoes and eagles; foxes (introduced into Australia) may be significant predators. In Tasmania the Tasmanian Devil will kill Echidnas; they even eat the spines!
Other than those predators, few animals can successfully attack an Echidna.
Echidnas have extremely keen senses of hearing and smell, and are able to detect the early approach of danger.
As soon as they feel threatened, they curl into a ball, protecting their soft belly and exposing only their sharp spines.
On soft ground, they can very quickly dig themselves into a protective burrow, sinking vertically within seconds and wedging themselves in with their very strong paws.
STATUS IN THE WILD
Echidnas are widely distributed and are not considered to be threatened.
So when you visit the echidna pen at Billabong Sanctuary, or are lucky enough to see one of these spiny anteaters in the bush, take a few moments to stop and marvel at the many extraordinary features of this amazing Australian animal.