Razorback and wild hog are Americanisms, loosely applied to any type of feral pig, wild boar or cross in North America. Common wild boar (Sus scrofa scrofa) are sometimes called "Russian boar" or "Russian razorbacks". The term "Razorback" has also appeared in Australia, to describe such animals there.
Introduction to the Americas
Christopher Columbus is known to have intentionally released domestic swine in the West Indies during his second voyage in order to provide future expeditions with a freely available food supply.
The practice of introducing domestic pigs into the New World continued throughout the exploration periods of the sixteenth and seventeenth centuries. It is thought that the Eurasian wild boar (Sus scrofa scrofa), which originally ranged from Great Britain to European Russia may have also been introduced. By the 19th century their numbers were sufficient enough in the Southern United States that they became a common game animal to hunt: in chapter seven of Mark Twain's late 19th century book The Adventures of Huckleberry Finn, Huck tricks his abusive father into thinking he's dead by shooting a wild hog he found in the woods and using the blood to smear around the cabin and escape, and eats the rest.
In South America, during the early twentieth century, free-ranging boars[clarification needed] were introduced in Uruguay for hunting purposes and eventually crossed the border into Brazil in the 1990s, quickly becoming an invasive species. Licensed private hunting of both feral boars and their hybrids with domestic pigs was authorized from August 2005 on in the Southern Brazilian state of Rio Grande do Sul, although their presence as a pest had been already noticed by the press as early as 1994. Releases and escapes from unlicensed farms (established because of increased demand for boar meat as an alternative to pork), however, continued to bolster feral populations and by mid-2008 licensed hunts had to be expanded to the states of Santa Catarina and São Paulo.
Recently established Brazilian boar populations are not to be confused with long established populations of feral domestic pigs, which have existed mainly in the Pantanal for more than a hundred years, along with native peccaries. The demographic dynamics of the interaction between feral pig populations and those of the two native species of peccaries (Collared Peccary and White-lipped Peccary) is obscure and is being studied presently. It has been proposed that the existence of feral pigs could somewhat ease jaguar predation on peccary populations, as jaguars would show a preference for hunting pigs, when these are available.
Feral hogs are a growing problem in the U.S. and on the southern Prairies in Canada. As of 2013, the estimated population of six million feral hogs causes billions of dollars in property damage every year in the U.S., both in wild lands and in agricultural ones. Because a swine's natural instinct is to root for tubers and seeds under the ground with its snout and tusks, a sounder of razorbacks can reduce acres of potatoes or corn fields to nothing in just a few nights. For commercial pig farmers, there is great concern that some of the hogs could be a vector for swine fever to return to the United States, which heretofore has been extinct in America since 1978. It is equally a public health concern that certain zoonotic diseases could jump to humans as waterborne illness: razorback sounders are known to defecate as they wallow in creek bottoms, washes, and other water sources that may be used or connected to sources of drinking water.
The present range of wild hogs includes all of the United States south of the 36th parallel North longitude. The range begins in the mountains surrounding California and crosses over the mountains, continuing consistently much farther east towards the Louisiana bayous and forests, terminating in the entire Florida peninsula. In the East, the range expands northward to include most of the forested areas and swamps of the Southeast, and from there goes up the spine of the Appalachian Mountains as far north as Upstate New York, with a growing presence in states bordering West Virginia and Kentucky. Currently Texas has the largest estimated population of 2.6 million razorbacks existing in 253 of its 254 counties. Outside the mainland, Hawaii also has trouble with feral pigs introduced to Oahu soon after Captain Cook's discovery of Hawaii in 1778, where they are a menace to very endangered birds and plants that the hogs eat voraciously. The population of razorbacks has exploded from only having 2 million hogs spread out over 20 states in 1990, to triple that number 25 years later, spread out over 38 states with new territories expanding north into states like Oregon, Pennsylvania, Ohio, and New Hampshire, some of them genetically mixing with escaped Russian boar introduced for sportsmen in between the early 1990s and the present.
Some aquatic animals like alligators and American crocodiles manage their numbers in the Southern swamps and South Florida, but as reptillian predators they are hemmed in by decreasing temperatures in fall and winter. Mid level predators, like bobcats and coyotes, may occasionally take piglets or weakened animals, but are not large enough to challenge a full grown boar that can grow to be three times their weight. In Florida, razorbacks make up a significant portion of the Florida panther's diet. The introduction of this non-native species wreaks havoc with the entire foodchain as wild hogs are omnivorous. Plants have a difficult time regenerating from their wallowing behaviors as North American flora did not evolve to withstand the onslaught of a rooting pig, unlike Europe or Asia. Small animals like the poults of wild turkeys, toads, and many species of turtles often fall victim to the larger and more aggressive swine, easily dominated and eaten or often consumed as eggs in the case of reptiles and birds The other wildlife that normally would prey upon these smaller animals are then left bereft of important food sources and in some cases outcompeted by the razorbacks higher reproductive rate: a sow can become pregnant as early as 6 months after her own birth and give birth to multiple litters of piglets yearly. Other animals, like the black bear, compete directly with them in the fall as razorbacks are notorious for consuming tree mast like acorns.
Compounding the problem is the shortened list of natural predators available in the United States to suppress razorback numbers. In North America, large predators that would suppress their numbers would include all subspecies of the gray wolf, the cougar, the jaguar, the red wolf, the black bear, and the grizzly bear. Unfortunately each keystone predator presents problems: the jaguar is extirpated from California and the Southwest. The grizzly, while native to most of the American West, is gone from the states that have huge hog infestations, namely Texas, Arizona, California, and New Mexico and the species has a very slow reproductive rate. Wolf numbers are overall weak and expected to remain so as they slowly repopulate their range; only one has thus far been recorded as inhabiting California in spite of thousands of miles of good habitat. The cougar is present in most of the West, but is gone from the East with no known populations east of Minnesota in the north and very thin numbers east of Houston in the South. The black bear, as illustrated, is both predator and competitor. Programs do exist to protect the weakened numbers of large predators in the US, but it is expected to take a very long time for these animals to naturally repopulate former habitat.
Alarmed at the overall population explosion, American hunters have in recent years taken to trapping and/or killing as many hogs as they can get their hands on, especially in Texas. Some have even turned the trapping and killing of razorbacks into small businesses. Legal restrictions on methods of hunting are fairly lax, as most state departments of wildlife openly acknowledge them as an ecological threat and some classify them as vermin: crossbows, professional grade bows and arrows, high powered rifles, semi-automatic pistols or revolvers, and military grade knives are weapons of choice. Many states do not even have a bag limit.
Hunting with dogs is permitted and very common, and has been practiced in the Southeast for generations. Competitions for who can produce the fastest hog dog are rife in the South, with Uncle Earl's Hog Dog Trials in Louisiana being the crown jewel, held every summer since 1995. Preferred scent dogs for catching feral pigs mostly are native breeds, and include the Louisiana Catahoula Leopard Dog, the Blue Lacy, all members of the Coonhound family, the Plott Hound, and the Blackmouth Cur; catch dogs typically are American Pit Bull Terriers and their crosses, and American Bulldogs. The method of hunting has little variation and usually the hunter will send out his bay dogs to chase the hog until it wears it out, then a bigger dog will be sent out to catch and hold down the hog (which can get very aggressive) until the hunter can come and kill it.
No one management technique alone can be totally effective at controlling feral hog populations. Research published by the Texas A&M AgriLife Extension Service suggests that harvest levels of 66% are required to hold Texas feral hog populations steady. Best management practices suggest the use of corral traps which have the ability to capture the entire sounder of feral hogs. Additional legal methods should be used as tool to further reduce feral hog populations in an area.
Appearances in popular culture
Following a long tradition of wild boar images in European heraldry, the razorback serves as an athletic image for the University of Arkansas in Fayetteville USA. The current live mascot's name is Tusk, a Russian boar. Fans of the team shout a chant derived from a domestic hog farmers' call.
Razorback is also the title of a 1984 Australian horror film directed by Russell Mulcahy, featuring a murderous and gigantic wild boar terrorizing the Australian outback. Other killer pig films include Pig Hunt (2008) by the late James Isaac and the Korean black comedy Chawz (2009).
An Australian razorback appears in the Disney animated film The Rescuers Down Under (1990). The Razorback is the name of a Space Marine tank in Warhammer 40,000. Razorback is the name of a boar-like humanoid subspecies in the popular massive muliplayer online role-playing game, World of Warcraft.