Researchers are teaching foxes not to eat freshwater turtle eggs, by making them feel sick
Uncle Allan Murray, Sharleen Sharp and Ligia Pizzatto. (ABC Rural: Annie Brown )
Tucked away in north east Victoria, about 15 kilometres from Wodonga, a restored wetland is fast becoming a haven for native birds, frogs and in particular, turtles.
Ryan's Lagoon sits within a 165 hectare nature reserve, that's under the care of the traditional owners from the Duduroa Dhargal Aboriginal Corporation.
It is where researcher Dr Ligia Pizzatto and volunteer Sharleen Sharp can be found, trekking in gumboots with a carton of eggs and a clipboard.
Ligia Pizzatto is trying to protect turtle nests by baiting them with chemically treated chicken eggs to make foxes sick. (ABC Rural: Annie Brown)
"We're trying to find different ways to protect turtles from fox predation," Dr Pizzato said.
The project uses taste aversion conditioning to deter foxes from eating turtle eggs.
"Basically, we're teaching foxes that eating turtle eggs will make them vomit," she said.
"It's an agricultural chemical that is already used to stop birds from eating grains."
The chicken eggs are injected with chemicals to make the foxes sick. (ABC Rural: Annie Brown)
The researchers inject chicken eggs with the non-lethal chemical and bury them in known turtle nests.
Once a week they come back to see if the foxes have taken them and bury new ones.
Checking the nests is no walk in the park.
On one of their treks, they spot two venomous snakes, flies swarm on their backs and the waist high grasses trigger hay fever.
A red-bellied black snake at Ryan's Lagoon. (ABC Rural: Annie Brown)
But despite the discomfort, they are excited to see that the foxes are learning to leave the eggs alone.
Juvenile turtles struggling
Dr Pizzatto said freshwater turtles are in decline in the Murray Darling Basin and the population is ageing.
"Foxes are very efficient — once the eggs have been laid, they can find them in just a few hours," Dr Pizzatto said.
Foxes eat turtle eggs. (Supplied: Ligia Pizzatto)
"In our region they are taking up to 90 per cent of the nests, so it really gives no chance for the population to recover."
"We used to have many more turtles," she said.
Dr Pizzatto is a biologist based at LaTrobe University and she based her study on data from Spain, where a similar method was used to protect ground-dwelling birds from foxes.
Ligia Pizzatto says she's excited to see that the fox conditioning is working. (ABC Rural: Annie Brown )
Her results so far have been promising, and some of the monitored sites are showing a significant drop in turtle egg losses.
"Lethal control is not efficient enough to protect nests because a single fox will still find all the nests of the season, so we need alternative methods." Dr Pizzatto said.
But she said lethal control was still needed to tackle foxes predating native animals.
"Unfortunately there's no silver bullet, but different methods can be used in conjunction to give these animals the protection they need," she said.
Juvenile turtles are extremely vulnerable to predators. (Supplied: Ligia Pizzatto)
Red European foxes were introduced to Australia in the mid 1800s, and still remain a significant problem as they prey on livestock and native animals.
The Victorian government runs a fox bounty program, offering $14 per scalp.
Fox scalps are covered in glitter so they cannot be re-submitted. (ABC Rural: Annie Brown)
Since the bounty started in 2011, Agriculture Victoria has received more than 1.2 million fox scalps.
Volunteer power
Dr Pizzatto's research involves weekly monitoring of eight wetland sites so she relies on the help of dedicated volunteers.
Sharleen Sharp, who spends hours at Ryan's Lagoon helping turtles, checks the cameras. (ABC Rural: Annie Brown)
Sharleen Sharp started the community group Turtles Albury Wodonga in 2018, when she saw turtles were being killed along the Hume Highway.
"We just try to help turtles in anyway," Ms Sharp said.
"We rehabilitate them, do school talks and community awareness."
Foxes are one of the biggest predators for turtles. (ABC Rural: Annie Brown)
When it rains, she also goes to the Lagoon to find turtle nests.
"The best way to find the nest is to follow turtles around in the rain, otherwise it's too hard to find. They cover it pretty well," Ms Sharp said.
"Raining nights, I can be out here for up to five hours."
Restoring habitat
The turtle is an important totem animal for the Duduroa Dhargal people.
If you look at Ryan's Lagoon from above, you can see the outline of a big turtle planted into the land.
Uncle Allan Murray says he wants to protect turtles and other local species. (ABC Rural: Annie Brown)
Uncle Allan Murray is a traditional owner and manages Ryan's Lagoon.
In just two years, his team has transformed the area into a culturally significant wetland.
"We're trying to bring this lagoon back to life," Mr Murray said.
"It was a cow paddock before we took over, although we still get a few cows in to help us manage the grass.
"This area was full of thistles and all sorts of burrs.
"We've been managing that and also put in the cultural learning scape so schools can come and visit."
Ryan's lagoon giant turtle can be seen from Google maps. (Supplied: Google Maps)
In December 2024, 185 megalitres of Commonwealth environmental water was pumped into the lagoon from the Hume Dam to help restore the wetland.
Mr Murray said the work being done by the researchers was important for collecting information.
Birdlife has increased at Ryan's Lagoon. (ABC Rural: Annie Brown)
"We want to re-establish and protect turtles, frogs and birds, and we want a little bit more information for future generations,"he said.
Many ecologists head to Ryan's Lagoon to conduct their research and Uncle Allan said he was happy with the partnerships they had formed.
"LaTrobe are the experts in the field, and they are doing a fantastic job with the turtles," he said.
"We're all working together for the common cause of protecting our local species."