Australasian Science: Australia's authority on science since 1938

How to Breed Echidnas

By Stephen Luntz

Andrea Wallage is discovering what makes an echidna frisky in preparation for efforts to save the endangered long-beaked species.

Like many zoologists, Andrea Wallage says she planned to become a vet as a child. “I always wanted to work with animals,” she explains. However, she says the choice to do animal science has meant she now works with far more interesting species. After all, how many suburban vets get to learn what makes echidnas happy?

Squashed echidnas may be a tragic sight by Australian roadways, but the local short-beaked species is not endangered. “They thrive in every ecosystem in Australia, from Mt Kosciusko to the deserts and from Tasmania to the wet tropics,” says Wallage. The same cannot be said in New Guinea, where three species of long-beaked echidna are all critically endangered.

“The long-beaked echidna is larger than the short-beaked species. They can weigh up to 17 kg and are hunted as a food source,” says Wallage.

“It is common when working with critically endangered species to first study a more common species. If you don’t know what you are doing you can make things worse rather than better,” says Wallage.

This is indeed the case with the echidna. “It was only a few years ago that it was thought to be almost impossible to breed echidnas in captivity, and most births were somewhat accidental and unplanned,” says Dr Steve Johnston of the University of Queensland’s School of Agriculture and Food Sciences. However, Wallage and Johnston have helped change that situation.

“Being monotremes, echidnas don’t have strongly regulated core body temperatures,” Wallage explains. Their temperature can vary by 15°C in a day, and they can go into torpor at even lower temperatures. Wallage believes the provision of an infrared light to each female echidna has helped make it easier for their subjects to maintain their temperature, and thus put them in the mood to breed.

Echidnas lay their eggs in one burrow before raising the baby in another after it has become too big for the pouch, so the provision of two nest boxes seems to have been appreciated.

Echidna babies are charmingly known as puggles, and present some challenges for their prospective saviours. “For example, we don’t know how to tell what gender they are until they are a few years old without expensive DNA testing. We don’t know when they become sexually mature, and we know very little about their reproductive cycles,” Wallage says. “They’re so different from other animals we can’t use a lot of normal techniques such as hormone analysis.

“It was thought that the females only have one puggle every 3 years, but we have now had a female produce a puggle 2 years in a row,” Wallage adds.

Although echidnas have been known to live for at least 40 years in captivity, the 3-year gap is not required to give the young time to develop. “After 10 or 11 months the mother and baby are doing their own thing, quite independent of each other,” Wallage says.

Instead, she suspects that mothers need time to build up the fat stores they use to survive while incubating the egg, which they do not feed. The provision of a rich ant diet may have helped overcome the lag.

It was once thought that echidnas could only mate once per year, but Wallage says: “We also discovered that the females can go through multiple ovulation cycles each season – one of our females showed signs of mating activity three times this season”. Such discoveries required considerable invasion of echidna privacy, with infrared cameras used to spy on Wallage’s charismatic charges 24 hours per day.

However, the results are clear. “We had two puggles born last year, and this year all five of the females have mated and four have produced puggles so far,” Johnston says. In contrast, fewer than 20 echidnas had been bred in captivity prior to 2012.

The puggles can now be viewed by the public at Currumbin Wildlife Sanctuary, and it is hoped they will soon be joined by their long-beaked cousins.

Wallage’s contribution has come in the course of her Honours and PhD at the University of Queensland, where she moved after studying Animal Science in Adelaide.