Western suburbs locals are being urged to drive slowly around local wetlands as vehicle strikes continue to threaten vulnerable nesting turtles.
Southwestern snake-necked turtles are unique to WA and lay their eggs from September to November, with significant populations at Lake Claremont, Jualbup Lake, Perry Lakes and Bibra Lake.
The species is currently listed as “near threatened” by the Department of Biodiversity, Conservation and Attractions, but local groups are concerned the reality is much more dire.
Director and former co-ordinator of Friends of Lake Claremont Nick Cook said not enough data was available to officially classify them as endangered, but scientists had observed a serious decline in population numbers.
Key concerns are road fatalities, predation from foxes and ravens, and habitat destruction, as 90 per cent of Perth’s wetlands have been destroyed over the past 150 years.
“The three big (issues) are foxes digging up the nests, and they say something like 95 per cent of nests are predated within 48 hours. Vehicle strikes — we’d love to encourage people to just slow down a bit on Alfred Road and Davies,” Mr Cook said.
“The third one is ravens; if they spot a turtle, they just turn it over on its back and go straight through under the arms, taking out all the good stuff, including eggs. And the turtle is often left conscious on its back dying.”
Turtle mortality rates can surge in nesting season as females migrate to find a nesting spot. This often occurs when the barometric pressure drops before a storm, causing turtles to move and expose themselves to danger.
“Our female turtles are really precious to us because they’re highly susceptible to predation or road strike, so they’re very vulnerable at nesting season and we obviously lose a percentage of them every year; that can lead to catastrophic population failure,” Mr Cook said.
“The other challenge is the recruitment, because once the eggs are laid, the hatchlings are on their own. You can imagine, it’s a long way to the lake when you’re only the size of a 50-cent piece.”
Mr Cook said FOLC originally set up a turtle tracker program with Dr Anthony Sontoro from Murdoch University, but now relies on its own volunteers to patrol the wetlands and protect any turtles they find.
Volunteers are armed with protection kits to place over nests, using a plastic mesh frame to cover the nest and protect it from predation.
“The volunteers just hang out doing laps of the lake, and when they spot a turtle they follow it and keep ravens and birds away from it, and follow it to wherever it goes to nest and hang out with it for a while until it’s done,” Mr Cook said.
“Then they either escort it back to the lake or pick it up and deliver it back to the lake.”
FOLC is also responsible for a major revegetation project at Lake Claremont planting about 400,000 native trees, which Mr Cook believes is the largest urban wetland restoration project in Australia and creates vital habitat coverage for turtles.
This was supported by the town, which also set up the Lake Claremont advisory committee in 2023 to meet quarterly and protect the local environment.
Mayor Peter Telford said turtles were most commonly spotted at Lake Claremont, the golf course, Scotch College playing fields, Cresswell Oval and Strickland Street, and the town was working to raise local awareness.
“The town has ‘care for wildlife signage’ focusing on turtles on Alfred Road, Shenton Road and Davies Road. There are also signs at the six entrances to Lake Claremont advising people what to do if they see a turtle and to make a report through the Turtle SAT app,” he said.
Friends of Lake Claremont also organises 45-minute walks around the lake, free for the community to join and learn about the wetlands. The next one will be held at 10am on October 26, starting at the Tree of Wonder statue.