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Unwelcome Invaders: Wild Pigs Pose a Serious New Threat to Idaho

Exotic species threatens agriculture, the environment and wildlife


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While Idaho and Oregon are in the early stages of learning to deal with wild pigs, Texas has been dealing with them since before it was an actual state. Historically, pigs were allowed to roam free, and people would occasionally have hog roundups, said John Young, mammalogist with the Texas Park and Wildlife Department.

But in the last few years, wild pigs in Texas have gone from an inconvenience to a major issue.

"There's no part of our environment that they don't impact," said Texas Wildlife Service's Bodenchuk. "They compete with native wildlife, they spread invasive plants, add E. coli to the watershed, eat endangered reptiles ... it's a train wreck that impacts us all."

Between 2003 and 2007, Bodenchuk said the wild pig population in Texas expanded by 20 percent per year. Even more telling is the fact that in 1982 the state killed 83 wild pigs, but by 2009 that number rose to 24,680, and the population is still considered out of control.

"We reached critical mass," he said. "We finally got enough pigs in enough places that we had populations interbreeding with each other. Populations grow slowly for a while, but once the second or third litters have their own litters, you have an exponential growth curve."

Bodenchuk's job has expanded to include traveling to other states to talk about the issues surrounding wild pigs.

"We serve as the bad example of what happens if you let it get out of control," he said with a resigned laugh.

Bodenchuk said Texas officials are using every method available to try to control the wild pig population, including trapping, snares, hunting, night-vision equipment and aerial shooting, which he said is the most cost-effective tactic.

But dealing with wild pigs is not cheap. Pigs cause an estimated $52 million in damage to just agricultural fields and pasture lands in Texas each year, Bodenchuk said, adding that the state does not compensate private landowners for damages. It breaks down to roughly $400 per pig per year. One 2007 study partially funded by the USDA estimated that damage to crops and the environment by wild pigs nationally is roughly $1.5 billion annually.

The ecological impact is harder to measure, but he points to the efforts to save endangered sea turtles, whose eggs wild pigs treat like an all-you-can-eat buffet.

"We're spending millions trying to beat the pigs to the nests," he said.

With 2 million wild pigs, Bodenchuk said eradication is off the table in Texas, but he still has hope that the population can be knocked down to manageable levels. He believes that with current technology and the cooperation of enough landowners, levels could be brought down by up to 70 percent.

To help in the effort, Texas researchers are working with an international group of scientists to create toxicants (poisons) that will work on wild pigs without endangering other wildlife.

Work is focusing on sodium nitrate--ironically the preservative in bacon--which limits red blood cells' ability to carry oxygen, which would basically put the pigs to sleep for good. The chemical is not dangerous to humans since we have a natural ability to counter the effects. Yet the challenge remains in creating a delivery system that wild pigs could get into but other wildlife couldn't. At this point, Bodenchuk said, wide use of the toxicant could be three years away.

In Texas, there are a few small slaughterhouses that specialize in processing wild pigs, taking advantage of the fact that it is legal to sell wild hogs as long as they are brought in alive for a pre-mortum inspection and the processing must be kept separate from other animals. Bodenchuk said roughly 90 percent of the meat is shipped out of the country as sausage.

The downside of the arrangement is that most markets will only accept pigs larger than 60 pounds, giving trappers a reason to release smaller pigs, Bodenchuk said.

Of course, the chance to go after a tough and elusive prey is tempting for some hunters. And while they might not go so far as to bring wild pigs into the state, they aren't opposed to taking advantage of an opportunity presented to them. It's because of this that wildlife officials have seen a bit of resistance to their efforts to get rid of the wild pigs in Idaho.

"They want to maintain it because they think it's fun," Flatter said. "They're not releasing more pigs, but they're keeping a low profile."

Hunters have played a key part in the effort to find the wild pigs by providing reports of sightings, as well as removing a fair number of pigs themselves.

"[Hunters] have probably killed more than the agencies have," Flatter said. "They had a jump on them. By the time we got up and rolling, the numbers of pigs were greatly reduced than they were four to five years ago."

In both Idaho and Oregon there is no season for wild pigs, which means hunters just need a valid hunting license. It also means there is no bag limit.

But before ambitious hunters grab their rifles, wildlife officials in both states point out that the pigs range across both private and public land, and there are some seasonal closures on public land.

While hunting would seem to be an effective way to keep populations in check, the overall impact of hunting is minimal.

"Anyone who shoots a feral hog is a friend of mine," Bodenchuk said, but quickly added that recreational hunting will never control the population. He pointed to reports from German game officials--where wild boars are actually a native species--that in a single year 600,000 wild boars were harvested, yet the population is still not in control.

"It's never worked anywhere in the world yet," he said.

Some states, including Kansas, are even banning the hunting of wild pigs in an effort to discourage hunters from bringing the species into new areas.

Still, many landowners in the area are working with state officials to trap the pigs as they learn more about the potential damages. Flatter said one landowner in particular started trapping on his own and has been rather successful. While hunters killed an unknown number of wild pigs last year, wildlife officials killed only one.

Landowner cooperation comes in part from a series of meetings in the Grandview area in which public officials explained the issue to area residents.

"We met with a lot of locals and businesses, and they were all on board," said London, adding that conservation groups were supportive of the plan as well.

"[It was nice] that we had everyone working together," he said.

The interagency team is working to first find where the remaining wild pigs are, and then to figure out how to get rid of them.

While officials say finding a limited number of pigs in a densely vegetated area is tough, they haven't emptied their tool box just yet. Bird hunting in the adjacent areas closed for the season at the end of January, allowing crews to track and attempt to capture the pigs. The timing means that not only will there be fewer people in the area, but it happens to be the best time of the year to track pigs since the foliage isn't filled in. The area is also subject to a spring closure to protect ground-nesting birds.

Officials have used hounds to try to track the pigs, but they're holding on to their last tool--aerial gunning.

"We have money for aerial gunning if the conditions are right," Flatter said, adding that efforts have been made to spot the pigs from the air during other missions.

However it's done, there is one goal: eradication. That last push is the hardest.

"It's much easier removing the first 20 than the last two," said Stopak.

"The problem is they can reproduce so fast, if you don't get all of them, it wouldn't take very long for them to rebound," Stopak said, adding that researchers estimate that 70 percent of the population would have to be removed each year just to maintain a stable population.

Bodenchuk has some advice for states who are facing wild pigs.

"Just say no," he said. "Get on them and get on them quick. We're spending several million a year--half a million directly from the Legislature--just trying to control feral hogs in Texas, and we're just chipping away at the edges. A single incident can be massive."