Just about everyone is familiar with pigs. They have been domesticated for thousands of years as a meat source and have permeated many facets of pop culture. Pigs are often used as symbols for some of the less pleasant aspects of human nature. Some people even keep them as pets. It should come as no surprise that as humans have spread across the globe pigs have as well and as a result they are one of the most numerous mammals on the planet, with over 1 billion individuals. Unfortunately, this is not necessarily a good thing. In many parts of the world pigs have managed to escape the confines of captivity and revert back to their ancestral, wild ways and as a result, feral hogs have now become a global ecological issue.
The ancestors of modern pigs first evolved in Asia about 34 million years ago and from there spread across Eurasia. They belong to the group of even-toed hoofed animals, the artiodactyls, but unlike most ungulates have four toes on each foot. Pigs are fairly large animals, with most species weighing multiple hundreds of pounds, and can inhabit a wide variety of habitats. They are omnivores that rely on their highly developed sense of smell to forage for whatever foodstuff is available, including fruit, grasses, fungi, roots, insects, eggs, carrion, and even the occasional small animal. A pig’s snout is tipped with a mobile cartilage disc that is as sensitive as a human finger and aides in uncovering hidden food. Male pigs, known as boars, often sport tusks which are primarily used for displaying to females and fighting. The upper and lower tusks constantly rub on each other as the pig opens and closes its mouth, which keeps them honed to a razor-sharp edge. Pigs were first domesticated between 5,000 and 7,000 years ago and archaeological evidence suggests that they were domesticated multiple times in different locations over the course of history.
What exactly is a Feral Hog?
By definition, a feral animal is one that is descended from a domestic species by has gone back to living as a wild animal. Sometimes these animals escape from activity and other times they are deliberately introduced. In the case of pigs, it is a combination of both. Being habitat and dietary generalists, even domestic pigs adapt to the wild readily and establish populations. Feral pigs can be found throughout the US and Canada, South America, and Australia. There are a few differences between true feral hogs and pure wild boar, which have also been introduced around the world and frequently crossbreed with domestic swine. Pigs with domestic ancestry have shortened snouts, dished-out faces, and more widely spaced teeth when compared to their wild counterparts. They may also sport the elaborately colored or patterned coats. Domestic pigs also achieve much larger size than wild ones, with some individuals topping half a ton, and any feral hog in excess of 700 pounds has domestic blood in it.
Why Feral Hogs are a Problem
Few animals make as effective an invasive as a feral hog. They can literally live anywhere and eat anything they come across, destroying the native species they consume and directly competing with those that need those same resources. A full grown feral hog is too large for most predators to tackle and given the fact that a female pig can produce multiple litters a year of up to a dozen piglets, their populations can quickly get out of control. Their foraging and wallowing habits erode local habitat, which decreases biodiversity and threats local species with extinction. Feral hogs also pose a problem to humans. Pigs are known to carry several diseases that transmissible to both humans and other animals. They causes tens of millions of dollars in agricultural damage every year, destroying crops, eating newborn lambs and calves, and stealing feed from livestock. Feral hogs that roam neighborhoods dig up yards, kill household pets, and even sometimes attack humans.
Dealing with Feral Hogs
There is no easy solution to the feral hog problem. Putting up barriers to keep pigs out works on a small scale, but pigs are very strong and can often overturn or dig under it. Trapping can be used to capture entire groups of feral pigs at once, but once other pigs seen their brethren captured they learn to avoid the traps. As a result, the most widespread method for controlling pig numbers is culling. Due to their intelligence and aggression, wild pigs have been popular sport animals since the ancient days in addition to being targeted as a source of meat. Due to their prolific breeding rate, even a heavily culled population can rebound back to its original numbers in as little as six months and it is expensive to maintain these large-scale culls on an annual basis. Scientists are investigating other ways to control feral hog numbers, such as by introducing contraceptives into the population. However, they have been unable to find a solution that does not also have potential negative impacts on local species.
For info on how animals were domesticated, check out out Mammal Center!
For info on how feral animals are impacting the environment, check out our Endangered Species Center!
For info on how to keep feral pigs off your property, check out out Living With Wildlife Center!