Why We Have More Wild Pigs

Invasive wild pigs, which includes wild boars from Europe and Asia, and feral pigs (wild pigs solely of domestic stock) are a huge problem in many states.

In localized parts of wild-hog range, you have some hogs that are black in color. These hogs have predominantly wild-boar genetic DNA and come from shooting preserves where they are bred and released into the wild for hunting. Feral pigs are domestic swine that have escaped into the wild — some hundreds of years ago, and others in more recent times. Those hogs are usually mixed color. If the wild boars are not harvested, they will most likely hybridize with domestic hogs, yielding more hogs of various colors. Regardless of color, wild hogs do well in the wild.

The reason there is a lot of interest in wild hogs is due to the massive crop damage they create. There are lots of studies on this damage, and suffice it to say, in many states it runs into the millions of dollars annually. That’s one reason why states that don’t have wild hogs, don’t want them. States that do, want to reduce and control them.

Not only do they damage agricultural commodities, but they transmit disease, compete with native wildlife, and are detrimental to the environment. Hunters, on the other hand, like wild hogs because they provide recreational as well as food value, which in some cases has led to the translocation and subsequent establishment of hogs in many parts of the country.

One recent study showed that state regulations to control hogs vary widely, which should come as no surprise given the fact that a few states have no wild hogs, some have had them for years, and some are just now getting them. The study showed that regulations have a big impact on hog populations, and states with permissive regulations tend to have the biggest hog problems.

Hunters have been known to import hogs from other states and release them to get populations started in the wild. Even where regulations make that illegal, it still happens. It’s not the problem it once was, but once feral swine are released into the wild, hunters must control them or there could be a population increase. Even then, hogs may be impossible to control.

The study concluded that states that have established hog populations will probably continue to have them. However, if states with lower populations enforce strict regulations, they may be able to keep the wild-hog problem from growing.

Dr. Sarah Chinn, from the University of Georgia, conducted a three-year study on hog reproduction, and it showed why we have hogs — even with strict regulations. She and her cohorts trapped hundreds of hogs on the 310-square-mile Savannah River installation in South Carolina. Of those captured, 514 were sows, and 492 of those were culled and necropsied to get data on reproduction. The remaining 22 were radio-collared and released. Thirty-one percent (160) of the 514 sows were pregnant. Of those, 50 were adults, 29 were subadults, 53 were yearlings, and 27 were juveniles.

Here are some numbers that show just how hog reproduction makes control measures difficult. Chinn found pregnant females every month of the year, but 47 percent were observed between February and April, and 31 percent between September and October. Interestingly, she found four sows that were pregnant and lactating at the same time. Female piglets reach sexual maturity in five to six months. These juvenile hogs don’t all breed, but they can. Wild sows averaged six piglets per litter but can have as many as 12. Sows can breed again five to six months after giving birth to a litter. Again, they don’t all do that — but they can.

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There are lots of variables that impact hog numbers in different states. For example, in my home state of West Virginia, 20 or so wild boars were taken from a West Virginia game farm in 1971 and released in a few southern West Virginia counties, where there was no rifle deer season. There still is no rifle deer season there, but there is a bow season. The reason wild hogs were released there is a bit complicated, but suffice it to say, a controlled gun hunt occurs there every year.

The West Virginia DNR has a good estimate of the number of wild hogs there and their dispersal, which has been extremely limited. Today, there is a seven-day season in late October and a three-day February season in southern West Virginia, and only 180 permits were issued in 2022. Archers can hunt hogs the entire season, beginning in September, and they can also hunt the three-day February season. No other state has a situation like what West Virginia has in four counties in the southern part of the state. Their control efforts have been working for years. Yes, there are occasional pockets of feral hogs that pop up in other parts of the state, but hunters have pretty much controlled that growth. This exemplifies why state regulations for controlling wild hogs are so variable.

Finally, if you think predation by the high numbers of coyotes found on Dr. Chinn’s study site in South Carolina might control pig numbers, think again. Coyote diet studies in that area showed that coyotes eat lots of things, but not hogs.

One coyote scat study done at the Savannah River installation found that in 146 coyote scats, none had any hog DNA. Coyotes can prey on very young piglets, but it doesn’t happen very often. Chinn goes on to suggest that the best approach to controlling hogs is to capture adult females and all her piglets at one time with baited traps, concentrating capture efforts during the peak breeding months of February through April.

Apparently, our earliest settlers brought feral swine as a food source for their settlements, and later settlers brought wild boars to America for hunting. They are now part of the landscape, and something our state and federal wildlife agencies must deal with. As you can tell, it is complicated — biologically and politically — and difficult.