‘Gosh they’re savvy’: It’s no porky, feral pigs are wreaking havoc across Victoria

The feral pigs can be difficult to spot with the naked eye, but Roger MacRaild knows well the signs of the extensive damage they inflict on both native bush and farmland.

Creek beds trashed and muddied. Pasture, native grasses and indigenous orchids uprooted and overturned, leaving large bald patches of bare earth.

MacRaild, who is Moorabool Landcare Network facilitator, said feral pigs destroyed the root systems of native grasses, which created a “cascade effect” by denying feed and habitat to other indigenous species.

Feral pigs caught on camera in Parwan, just 45 kilometres west of Melbourne.

He said native mammals tended to gently turn over soil, and this behaviour helped to propagate native fungi.

“The pigs have taken that principle and turned it into something extremely destructive,” he said. “There’s a suite of native species that are displaced by the pigs.”

The animals might lack the lust for human blood like the boar depicted in the classic Australian schlock horror film Razorback, but they are every bit as dangerous for the natural environment and agricultural land.

Wild pigs are spreading in Victoria and are becoming entrenched in much of the state. They are now pushing closer to suburbia, having become established in the Lerderderg State Park and surrounding farmland, which is near the growth area of Bacchus Marsh. They are spreading in the Werribee River corridor, too.

Roger MacRaild inspecting the landscape where feral pigs have invaded.Credit: Jason South

MacRaild said increasing signs of damage caused by feral pigs and detections by cameras on farms indicated numbers of the invasive species were growing in the region north-west of Melbourne. He said the animals were able to survive in a range of Victorian environments.

“Being omnivorous is a big part of it. They’re incredibly intelligent animals, too.”

He called for a co-ordinated response from government land managers, including Parks Victoria, so that private landholders could tackle the problem and drive down feral pig numbers.

Farmer Jo, who asked not to reveal her surname, hopes to avoid a feral pig problem on the scale of NSW, Queensland and northern Australia, where the animals have reached plague proportions.

“That is probably my greatest fear,” she said.

Farmer Jo on the creek bed that’s been previously damaged by feral pigs. Credit: Jason South

The federal Environment Department estimates up to 23.5 million feral pigs are established across about half of Australia.

Jo, a cattle and sheep farmer and trained veterinarian, will generally only catch a glimpse of the pigs if she is downwind. Otherwise, the wind can carry her scent and the sound of her movement through the bush. “Gosh they’re savvy.”

Jo, who farms north-west of Melbourne, has mounted motion sensing cameras on her property to detect the movement of pigs and determine the best places to lay bait. She uses a substance called Hoggone, which targets feral pigs and renders them unconscious before they die.

“They effectively faint.”

Farmer Jo and Roger MacRaild observing damage from wild pigs.Credit: Jason South

Jo observed that the COVID-19 lockdowns emboldened feral pigs populations because there was less human presence. On her property they appear to follow the flow of water – tracking along a creek that runs beneath the steep terrain.

Australian Pork Limited national feral pig management co-ordinator, Heather Channon, said the animals were well suited to Victoria’s cooler climate.

“Because they’re very resilient and adaptable they can live across quite diverse landscapes,” she said.

Channon, whose position is funded by the Department of Agriculture, Fisheries and Forestry, said pig pregnancies typically lasted three months, three weeks and three days with a sow able to produce up to 12 piglets in a single litter. They can have two litters within a 12 to 15-month period.

Damage caused by feral pigs in Bullengarook near Gisborne to the north of Melbourne.

At that rate, land managers needed to remove at least 70 per cent of wild pigs in an area just to maintain steady numbers over a 12-month period, Channon said.

She described feral pigs as indiscriminate eaters whose diets could include threatened flora and even earth worms.

She said they also posed a major biosecurity threat because they could transmit dozens of diseases. This could include foot and mouth disease and African swine fever if they were introduced in Australia.

Parks Victoria district manager David Petty insisted his agency worked with private landholders to monitor hotspots in the Lerderderg State Park and Werribee Gorge State Park where domestic pigs periodically escaped from private properties.

Baiting of feral pigs one of the few options available to farmers to control the introduced species.

“It’s important we control these pigs-run-wild because they will eat almost anything they can lay their snouts on and regularly turn over large areas of soil in search for food such as roots, tubers, fungi and insects,” he said.

Invasive Species Council advocacy director Jack Gough said authorities needed to maintain a consistent focus on managing feral animal numbers, rather than just throwing money at the problem when populations exploded.

“Actually, the time to be doing effective feral animal management is after drought and bushfires,” he said.

Gough said plentiful feed had resulted in rising numbers of feral pigs, deer, rabbits and goats in much of Australia, including Victoria. He said feral pigs did immense damage to soil and waterways.

“The environmental impact of feral pigs is hard to overstate,” he said. “We call them mini bulldozers. They stop regeneration of plants.”

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