Herald editorial board

North Dakota has a wildlife immigration problem on its hands as feral pigs continue their northward migration and are being spotted in the state.

Friday, a brief story in the Herald noted how the North Dakota Game and Fish Department is reminding hunters that shooting and trapping feral pigs is illegal within state borders. Don't be fooled by the short story and its small headline - it's a big deal. Wild pigs exist in North Dakota and could grow to be an outright nuisance.

Two years ago, a report on the Game and Fish Department website reported the first feral hog sighting in the state came in 2007 and on numerous occasions since then. In the years since, state and federal agencies have worked to eliminate the critters due to their threat to livestock and property.

Feral swine are not native to the United States but were brought here as a food source centuries ago. According to the United States Department of Agriculture, their population is at 6 million and expanding quickly. The USDA says the pigs move to new ranges as they adapt to climates, are transported by humans and as they find areas with a lack of natural predators.

Maps compiled by the USDA show steady expansion of the feral swine range since 1982. Back then, it generally was limited to Florida, southern Texas and parts of California. Today, the range encompasses the entire Southeast and numerous other states. Sure enough, on the USDA's most recent map, there is a small patch of color - indicating feral pigs - in the Turtle Mountain area of North Dakota.

Many states have sport hunting seasons on feral pigs, but North Dakota does not. So far, eradication efforts have been solely limited to government agencies. For instance, the report on the North Dakota Game and Fish Department website notes that "several state and federal agencies have taken aggressive action to eliminate suspected feral pigs." This is good.

And remember: The state sent its reminder this week that feral pigs cannot legally be shot in North Dakota. An exception, apparently, is for landowners who feel wild swine pose an immediate threat. Any landowner who takes this step must contact the Board of Animal Health within 24 hours.

The USDA has estimated feral hogs annually cause $1.5 billion in damage nationwide, although a study at the University of Georgia places damages as high as $2.5 billion. Damage from the swine can come in many forms: Irreparably rooting of the land, consuming and trampling crops and spreading disease to domestic livestock. They also can ruin habitat and crowd out wildlife.

Some states - South Dakota and Wisconsin, for example - in recent years urged people to shoot feral hogs on sight. That seems to us the best suggestion, but again, remember: Hunters cannot legally do that in North Dakota or Minnesota, and landowners are urged to be prudent when feral hogs are spotted.

Therefore, the best option after seeing a wild pig is to call the North Dakota Game and Fish Department at (701) 328-6300 or a Minnesota Department of Natural Resources wildlife office; for example, the Thief River Falls office at (218) 681-0946.