Feral pigs are invading America and no one quite knows how to stop them

Feral pigs are invading America and no one quite knows how to stop them

One little piggy went to market, one little piggy stayed at home, one little piggy had roast beef, one little piggy had none, and one little piggy went wee wee wee leaving a trail of epic destruction across America. It’s wasn’t the ending you were expecting, was it? But while much has been made of American public health issues, there’s another problem slipping under the radar right now: the ever-increasing impact of feral swine. At present, it is the southern half of the USA that is particularly overrun by the creatures, but there are now an estimated six million pigs spread across 39 states nationally.

But these aren’t the friendly little Babes of your favourite films. No, these are something different entirely. Believed to carry over 30 different types of diseases and parasites, the US Department of Agriculture (USDA) has declared the feral swine “a harmful and destructive invasive species”, that destroys public property, threatens native ecosystems, and poses a risk to the health of livestock and humans alike. According to a report from The Journal of Applied Ecology, within the next few decades the problem is one that will affect every single county in mainland USA - and even worse, authorities have no idea how to stop it. 

The swine running wild are also taking quite a hefty toll on the national piggy bank, costing the US government $1.5 billion per year between the price of repairing the damage they have caused and implementing methods to attempt to control their spread. As the pig population continues to rise, that figure is only going to get higher. In 2014, the government agreed to provide the USDA with a $20 million injection of cash to help put in place “anti-invasion” measures, designed to stem their tide though it is not clear yet how much of a difference this is going to make.

So far, the impact appears to have been negligible and scientists have now predicted that they will continue to spread North - and if the researchers' track record so far is anything to go by, they’re probably right. They correctly predicted 86 per cent of the counties that the boars spread to in 2012. While the most keenly affected states are still California, Florida, Oklahoma and Texas, scientists have noted that in the last few years, their average rate of expansion has almost doubled from 6.5km per year to 12.6km per year, with more and more counties being hit by the issue.

This expansion into northern areas appears to have been driven by one key factor: climate change. Milder winters are making the traditionally chillier northern states more hospitable than ever for the feral pigs, with increased opportunities to find food and survive in the wild. It seems the pigs are getting bolder too; no longer the preserve of rural settings, it is now increasingly common to spot them ravaging your back garden, digging holes in your local golf course and tearing up city parks.

In a way only America can, many have seen guns as the answer to the problem, and in the state of Texas, where there are estimated to be 1.5 million pigs on the loose, hog hunting has become big business. With no limits on how many hogs one person can kill - or even catch alive and take to the slaughterhouse - some traders have even set up hog hunting packages, complete with machine guns and helicopters. 

However, even if 70 per cent of the pigs in a region are killed, those remaining can still reproduce fast enough to restock that population in just two and a half years. That’s a whole lot of grunting - so much so that some are now advocating the use of pig contraceptives to stop the pigs from breeding. Also problematic is the tactic of setting up traps to catch hogs alive because, given that they tend to move in packs of eight to 15 animals, it is almost impossible to catch all of them at once: "It's not how many pigs you remove," said Mark Smith, an animal specialist at Auburn University. "The real question is, how many pigs did you miss?" 

So is there anything that America can learn from the animal infestation problems of other countries? Well, authorities in Paris are currently pondering how to deal with the rat infestation in their city, where rodents now outnumber people by four to one. More specific to the issue of feral pigs, Canada and Australia are also fighting their own battles. In Australia, where feral pigs now outnumber humans, the use of sodium nitrate as a poison is now commonplace and yet the animals are still regarded as a serious problem, causing widespread damage. 

All in all, it’s hard to know if the money that the USDA is investing in pig control will help. But given the problems that other nations are having controlling their own feral swine populations, combined with continuously rising temperatures and the pigs' ability to reproduce at an alarming speed, it's hard to see how they will. Conveniently, hunting groups with money to make have also pushed back against any plans to poison the pigs, which can't help either. So, having been ignored as a problem for so long, it seems now that this may be a case of bolting the sty door after the proverbial pig has bolted.