Underneath the farmland of Gippsland lurks one of nature’s strangest curiosities: a gigantic, wriggling earth worm about as thick as a twenty-cent piece and often more than a metre long. 

Known to locals and keen invertebrate enthusiasts across the world, the Gippsland Giant Earthworm has been a tall-tale, a Real Life Epic, and was once at the centre of its own worm-shaped museum. 

But now the Gippsland icon is under threat and has been listed as vulnerable by conservationists. In 2012, the long, winding Giant Earthworm Museum shut its doors for good, and since then the national treasure’s star has slowly burned out.

CAN THE WORM TURN?

But a 2024 research project is hoping to reignite interest in the worm, aiming to improve its chances of survival and reinvigorate a sense of local pride in an animal that was once so well known that Sir David Attenborough came to visit it.

Even though it’s a curiosity, there is still much to be known about this mud-loving invertebrate, as its lifespan and breeding habits remain somewhat of a mystery to researchers and scientists.

The Gippsland Giant Earthworm is currently listed as vulnerable under the Environment Protection and Biodiversity Conservation Act, but a research project that began last year helped reignite an interest in Gippsland’s most distinctive invertebrate and hope to improve its chances of survival.

HISTORY OF THE WORM 

The Gippsland Giant Earthworm lives exclusively in a 40,000-hectare area in south and west Gippsland. The first recorded sighting of the worm was in 1878 when railway workers dug them up while constructing rail tracks through the region. 

Even though the worm is unique, it would take a long time for researchers to understand its strange burrowing habitat and the ideal conditions for it to procreate.

Dr Beverley van Praagh has studied the Gippsland Giant Earthworm for over 30 years. 

In the early 1980s she took a position as a research PhD student with La Trobe University, and was told about the worms by a professor. Recalling that time, she said: “I was really fascinated by the sound of these amazing, enormous creatures, and how there was not very much known about them.”

POCKETS OF WRIGGLERS

The way in which the giant earthworms are studied has changed dramatically over the past 40 years.

“Back then they weren't protected, so we were often digging them up,” van Praagh said. “Now we don't pick them up at all unless there's a real reason for it.

Predictive modelling is now the standard way researchers locate pockets of worms in the landscape, so understanding the ideal conditions for the worm’s habitat is increasingly important.

Dr van Praagh says that you can hear the giant earthworms underground when you’re walking on their soil: “They make this gurgling sound, like water running out of a bath. The gurgling suction sound is made because their burrows are quite wet, and they move quickly from one pocket to another.”

GIPPO WORM BACK IN FAVOUR

The worm’s status as an oddity might be part of the reason why studying its habitat has been increasingly alluring to researchers. Dr van Praagh has observed that “a lot of research money goes towards cute, cuddly and furry animals, and not so much towards animals without a backbone, but we are lucky that the worm is a bit of a curiosity”.

One of the reasons they're so fascinating is that they’re found in very small pockets of habitat. You can walk along a creek bank or a hill slope and find a colony that's restricted to an area of a few metres squared. 

Dr Michael Aberton has been an ecologist for 25 years and was working at Water Technology when he was approached about leading a pilot study into understanding the effect of water hydrology on the worm's habitat.

TOO WET FOR THE WORM

The study compared soil properties within the community while using local weather data to observe the effects of rainfall on worm populations. It's been postulated that the Giant Earthworm doesn't like soil being too dry or too waterlogged.

By observing the varying conditions of the soils, including water, temperature and oxygen levels the study aims to understand this issue. Dr Aberton says the hypothesis “is that waterlogged soils will not have much soil oxygen in them. And that's why they're not conducive to the Earthworm”.

The vast majority of the worm colonies are located on private property, so collaboration with farmers has been an important step to locate pockets of the species.

“We're lucky we’ve got a landholder who's also a scientist, he's been really good in offering us help. He's got an interest in science and wants to know more about this species as well,” said Aberton.