Dave Rose

The insatiable appetites of feral pigs mean that some staple species of Australian wildlife can face unwelcome harassment and even have their status endangered.

Unlikely as it seems, wild pigs have targeted sea turtles as food sources. And their voracious feeding habits are indirectly affecting the fate of koalas. The gluttonous swine gorge on any foliage they come across, which means wrecking the leafy landscape and its surrounds that the koalas frequent.

The koala population is in enough trouble as it is, due to the effects of defoliage and the last thing that they need are feral pigs having an unwanted influence. Make no mistake ‑ if the pigs need to nosh, their instincts know no bounds. When drought has gripped in areas frequented by hogs, there are tales of desperate groups of them attacking tiny calves.

Deborah Tabart, CEO of the Australian Koala Foundation, has not seen any evidence on her many travels around Australia, to consider feral pigs an immediate danger to koalas but is still concerned.

“I have never heard of wild pigs eating eucalyptus trees, but I wonder whether their destruction of the ground when they burrow for food would stop the regrowth of koala food trees,” she said.

Deborah resides in Queensland but her roving duties take her all over the continent. She worries that attempts to eradicate certain pest creatures can have a rebound upshot for other breeds of wildlife. Perhaps baits put down could be munched by unknowing innocent parties such as pets wandering onto properties they shouldn’t.

“I remember on Kangaroo Island, when our teams were researching landscapes, seeing a huge, I mean huge, feral pig that just appeared to be burping after eating a bait. He was enormous, like the size of a hippopotamus,” she claimed.

The pigs themselves are faced by apparatus and tactics to curb their antics but they give the impression of being as clever as they are brash.

“There were pig cages all over the island. Big cages!” said Deborah.

If the koalas have largely escaped direct suffering at the hands of the marauding feral pigs, other groups have not been so lucky. It is estimated that there are least three million porkers, perhaps even more, roaming Cape York Peninsula, eating whatever they can.

They possess the perfect genetic credentials to survive and thrive in this harsh tropical landscape. As the pigs multiply, they ride roughshod over other species. This is certainly true in the case of the turtles that breed along the beaches of Western Cape York.

In many examples, including one as reported by the ABC, feral pigs are preying on nests of newly-hatched flatback and green turtles along the north Queensland coast. The pigs are apparently guzzling a combination of eggs in nests and turtle hatchlings.

Feral pigs dig up turtle nests not long after mother turtles lay their eggs in the sand, then wolf them down and often come back for another helping when the eggs are close to hatching. At some locations, Rangers and scientists have observed 100 per cent of turtle nests eradicated by pigs. Other raiders will chomp on turtle eggs – dingoes and goannas in particular ‑ and various creatures try to move in on the hatchlings as they crawl along the dunes on their way to the sea. But the pigs scoff more eggs than other killers, and there are so many of them that the turtles don’t stand much of a chance.

“In northern Queensland, feral pigs are still an issue in relation to the turtles,” said Christine Hof, Marine Species Project Manager with the World Wildlife Fund (WWF).

“It is a real challenge to address the threat of feral pigs but there are organisations which are having success.

“The Western Cape Turtle Threat Abatement Alliance is one of those. They are doing some incredible things.

“Don’t forget the turtles are also under threat from goannas, plastics being washed ashore as well as climate change.

“It is a finite balance between native and feral animals and very complex.”

That view is echoed by Kerri Woodcock, Coordinator of the Western Cape Turtle Threat Abatement Alliance. Kerri has more than 10 years experience in community-based natural resource management and has worked primarily with the coastal zone. Kerri supports the WCTTAA member organisations (Kowanyama, Pormpuraaw, Napranum, Mapoon and Northern Peninsula Area Councils) whose goal is “to efficiently manage threats to coastal habitats and enhance opportunities for nesting marine turtle populations of the Western Cape”.

“The greatest direct threat to marine turtles on the Western Cape is the predation of the turtles’ nests by feral pigs,” said Kerri.

Something had to be done to halt the incursions on the turtles and one of those options is culling of the feral pigs

“We carry out aerial culling programs as well as land culling programs,” said Kerri. “The culling is carried out by Indigenous Ranger groups on Indigenous land.”

Such procedures are embarked on under the auspices of the Nest to Ocean Turtle Protection Program, with the support of Cape York Natural Resource Management. The program involves the Australian and Queensland governments each committing corresponding funds of up to $3.5 million across six years until mid-2020 to help lessen the perils of predation on marine turtle nests.

“It’s not cheap to send a chopper up in these remote areas, so by coordinating and prioritising our efforts, we can be more efficient and effective,” said Kerri.

It seems like a full-time task to stem the intimidation imposed on the turtles by the feral pigs but Kerri is encouraged by the way things are heading.

“Are we winning the battle? ‑ at the moment,” she said. “The WCTTAA Ranger groups work tirelessly throughout the turtle season on the remote coastline of the Western Cape to protect the turtle nests. Aluminium cages are used to cover the nests of the endangered turtle species, to protect them from the pigs that are missed during culling activities.

“For the last three years the beaches monitored by the WCTTAA groups have had predation rates averaging 10 per cent. At one stage during the early 2000s, that was running at about 90 per cent.”

Damien Ferguson, President of the Sporting Shooters’ Association of Australia Queensland Conservation and Wildlife Management Division, knows all about the miscreant tendencies of feral pigs in his neck of the woods and their ability to adapt to varying conditions.