It's not uncommon for the odd cane to hop a ride on a truck or car and hitchhike down the east coast of New South Wales, but a growing number of these warty, toxic pests have made their way to a private property an hour's drive north of Sydney, and the threat is being taken seriously by biosecurity experts.
The cane toads were found hiding under a sheet of tin on a private property in Mandalong, a suburb of southern Lake Macquarie in the Hunter region.
The NSW Department of Primary IndustriesNSW Department of Primary Industries DPI biosecurity team admits it is possible that the invasive pest has been breeding on the property.
If this proves true, it says that the potential for explosive numbers to emerge during the summer months is an unwelcome but real prospect.
We're still getting to grips with how big a problem this is and we won't know until we have a few weeks of community reporting to see how far out this population may go, said NSW DPI biosecurity manager Quentin Hart.
The toxin-oozing cane toad is widely acknowledged as a destructive predator that can devastate native animals and ecosystems. They can poison domestic pets if they are swallowed.
A total of 17 cane toads were found at the property.
The NSW DPINSW DPI has confirmed the discovery of two toads in a subsequent search.
Mandalong is located more than 500 kilometres south of an established cane toad containment zone around Clarence Valley on the NSW North Coast.
It is believed to be the first significant outbreak of cane toads beyond that buffer zone since 2010 when the amphibians took up residence in Sydney's Taren Point.
Why did the toads breed on-site or were they unknowingly hauled in as tiny toads in garden supplies or some other item brought onto the property?
We may get lucky, it may be confined to this very local area, said Hart.
It seems likely that the toads will be much harder to eradicate if they did breed locally from tadpoles.
The cane toad is an introduced pest that was brought to Australia in the 1930s as part of a biological control program for beetle pests that affect the sugar cane industry.
According to conservationist John Clulow, a former associate professor at the University of Newcastle, they are more prolific breeders than rabbits.
A decent breeding size female can produce 25,000 to 35,000 eggs in a single season, he said.
Most of the people in a good breeding event would be fertilised and turn into tadpoles in a pond. Professor Clulow has been assisting the NSW DPI response since the toads were discovered last week, including testing of tadpoles in a nearby waterway.
So far, only native frogs have been identified.
One of the toads in the Mandalong cluster was a fully developed reproductive-aged male.
The possibility is that they may have been the result of a breeding event down there at Mandalong, Professor Clulow said.
That is the real concern here and I think we may have a problem with DPI and biosecurity people on our hands. Numbers can be explosive, according to Professor Clulow, especially when cane toads move into new areas.
He said that it can be devastating for the native fauna if a population moves into a new area.
The NSW DPINSW DPI is encouraging all residents to keep an eye on cane toads and report any sightings to the DPI Biosecurity Helpline.