Experts say feral pigs are becoming increasingly bold and encroaching on outer suburbia as a population boom drives them into more densely populated parts of Queensland.
Pigs have been wreaking havoc for landholders in suburbs less than 10 kilometres from Rockhampton's CBD, while a sighting at a Gold Coast school in August has also raised concerns.
Recent sightings by bushwalkers have occurred at Cunningham's Gap and Mount Cordeaux in southern Queensland, with high numbers also reported around Dalby on the Western Downs and Drayton on the outskirts of Toowoomba.
Darren Marshall, from the natural resources management organisation Southern Queensland Landscapes, said favourable conditions had led to a bumper breeding season.
"I think we're coming into a really, really bad time for feral pigs," he said.
"Everywhere that we've seen, all the sows have got lots and lots of piglets on the ground.
"There's so much food around, they breed so fast and re-infest so quickly."
The problem is also happening around the world with reports last week that Rome's booming wild boar population had trickled out of city parks and onto the streets.
On the move
Mr Marshall said the pests were becoming increasingly bold as competition for food intensified.
"I think people would be amazed how close they come in, looking for that food source, to residential areas," he said.
"They're more than happy to take risks to get to areas where the food sources are.
"They are at the back of new residential estates.
"And if you're walking through the bush and there's a 60 to 100 kilo animal beside you, rustling through the scrub ... it definitely does scare you."
Hiker Kirsty Sutton, from Gatton, said she had seen plenty of evidence of feral pig activity along walking trails at Cunningham's Gap in the Main Range National Park.
She saw one of the animals there for the first time in June.
"I was walking down one of the tracks and I could hear one ... starting to approach the track," she said.
"My first thought was just, I have to run, I have to get away.
"I just screamed at it and then started running up the side of the mountain as fast as I could.
"I was quite surprised. Because it is such a well-walked area, I wasn't expecting it."
Australia's $100m problem
The impacts of feral pigs cost the nation's agriculture sector more than $100 million annually, according to Biosecurity Queensland.
The Rockhampton Regional Council said it had trapped and euthanased around 50 of the animals in the past few months, in response to increased sightings close to the city.
"The pigs were encroaching on residential land, ripping up people's yards to find food," planning and regulation councillor Grant Mathers said.
He said sightings were most common in areas that backed on to state parks, including Frenchville, Norman Gardens, Mt Archer and Koongal.
The South Burnett Regional Council also said there had been a "significant increase" in pigs over the past decade, with popular tourist site the Bunya Mountains a particular problem area.
"Not many years ago, there were no pigs in the South Burnett," councillor Scott Henschen said.
"As a primary producer I can definitely say that there is now a problem.
"Landowners have been fairly diligent about it; however, it doesn't take much and they can multiply tenfold pretty quickly."
What is being done?
A national feral pig management coordinator was appointed in March 2020 and handed down a draft action plan — the first national coordinated strategy to tackle the pests — earlier this year.
The plan advocates using a range of methods to control feral pig numbers, including baiting, aerial and ground shooting, trapping and exclusion fencing.
Within Queensland, authorities are using $25 million from the Queensland Feral Pest Initiative to construct cluster fencing and implement management programs for a range of invasive species, including pigs.
From a safety perspective, Darren Marshall said residents or bushwalkers who came across a feral pig should give it a wide berth and notify authorities as soon as possible.
"Don't try to corner them or do anything but let people know where they are," he said.
"I've worked with pigs for 15 years and have come across a few cranky ones, but most of them just want to get away.
"The best thing people can do is give them space."