Biospeaking: Alien Bacon
— James Earl Kennamer, Ph.D
James Earl Kennamer, Ph.D.
There is a story unfolding in North America that reads like a Hollywood horror movie. Alien invaders are moving across the landscape from coast to coast, devouring all manner of things in their path, destroying the inhabitants, carrying disease and reproducing at a fantastic rate. No, were not talking about green men from Mars, or a malignant version of E.T. This invasive alien is Sus scrofa: in laymans terms, wild, or more correctly, feral hogs. Theyre not from another planet, but they are from another continent, and they dont belong here.
Many hunters, as well as the general public, may be unaware that hogs are not native to North America. A related species, the javelina, is native to the southwestern United States and Mexico, but thats all. The first domestic hogs arrived in the Southeast with the Spanish explorers, probably in the early 1500s, and it didnt take long for the escapees to become feral. As more European colonists arrived in the New World, they brought their hogs with them, often letting them run wild and forage on the bountiful food available, and hogs eat just about anything.
Over the centuries, feral hog populations have increased and their range has spread, primarily across the Southeast, with major river systems providing ideal travel corridors for hog expansion.
One major problem with feral hogs is their incredibly high reproductive rate. Female feral hogs (sows) may breed as early as 6 months, and litter size may range from four to eight, occasionally even more, with older sows producing the most pigs. The gestation period is about 110 days, with some sows producing two litters a year. Feral hog populations can easily double in just a year or two.
Appetite for destruction
Feral hogs are omnivorous and opportunistic, and they survive on an incredibly wide range of food items. Preferred plants include acorns, beechnuts, wild plums, blackberries and the tubers of many types of sedge, including chufa. Not so obvious, but also used by hogs, are cactus and the roots of longleaf pines. In addition to native plants, crops like corn and soybeans may suffer extreme damage where feral hog populations are high. Ask your local farmer how they feel about feral hogs and youll probably get an earful.
Most of us know hogs eat plants, but they also consume animals, whether by scavenging or by predation. The list of species feral hogs are known to eat includes white-tailed deer fawns, domestic lambs, other hogs, snakes, bird eggs and much more. Incredibly, woodcock, grouse and several duck species have been found in feral hog or wild boar stomachs as well.
Research has shown feral hogs likely have an impact on nesting wild turkeys, too. In Texas, turkey nest success and poult production were notably improved after intensive feral hog control efforts greatly reduced the study areas population. Hogs may also be directly competing for some of the same resources needed by turkeys. Chufa plots planted for turkeys are a favorite target of hogs, often resulting in destruction of the plot before the turkeys ever get a chance to use it. Some habitat managers and landowners have stopped planting chufa due to hog damage.
The impact of feral hogs is not limited to what they eat. Their characteristic rooting behavior as they forage for food creates a serious habitat change, with bare ground opened up for invasion by weeds. Tree roots may be damaged too, sometimes killing the tree or creating an entryway for disease or insects.
In addition to their prolific reproduction and omnivorous nature, hogs are seldom held in check by predators. Certainly, some pigs are lost to predators, but adult hogs are big and tough enough that all but the largest predators will give them a wide berth. Disease affects hogs, and some mortality results from brucellosis and pseudorabies, but often the hog survives them, becomes a carrier and may pass them along to domestic livestock and humans.
Until the last 20 or 30 years, most feral hogs on the continent were confined to the Southeast, with some pockets in California and elsewhere. That has changed drastically, with feral hogs now found in at least 39 states and four Canadian provinces. Not only has feral hog range increased exponentially, their numbers have too. In 1991, the continental population was estimated to be 1-2 million. Now, Texas alone has a population estimated at 1.5 million feral hogs and growing rapidly.
Some of this expansion has been natural, with hogs moving up rivers and valleys into unoccupied habitat. However, most of it has been due to trap and transfer, whether legal or illegal. In other instances, hogs have escaped from game farms and quickly established populations.
We have a prolific, omnivorous invader that has occupied much of the country. What are we going to do about it? If may be fair to say no one knows for sure what to do to control feral hogs. Weve tried legal hunting within established seasons and year-round hunting without limits, neither of which has done much to reduce, let alone eradicate, feral hogs. More extreme and arguably more effective methods of control include trapping, hunting with dogs, night hunting with special optics and even aerial gunning from helicopters. In some cases, hogs and been captured, fitted with radio transmitter collars and released to be Judas pigs. These hogs, especially sows, return to the herd or sounder, as groups of hogs are often called, leading to the eradication of the whole group. Even with all these methods in use, feral hogs continue to spread.
Bring home the bacon
We encourage NWTF chapter participation in all legal means of control, and support events designed to help. Education is important too. Hog hunting can be fun and exciting, even profitable for some, and trap and transfer, both legal (rare to nonexistent now) and illegal, has been the major vehicle for range expansion. To help stop this, we all need to speak up at every opportunity with the facts on just how damaging feral hogs are to our native wildlife and habitat. To put it in a form all turkey hunters can understand, more feral hogs mean fewer wild turkeys.
Is that a trade-off you are willing to make?