Practical information to identify and manage non-native, invasive plants and animals
The Quiet Invasion:A Guide to Invasive Species of the Galveston Bay Area
Sus scrofa
| ITIS TSN: | 180722 |
| Presence: | Current Invaders |
| Habitat: | Terrestrial |
| Native Range: | Europe and Asia |
Human Health
Feral hogs carry swine brucellosis, an infectious disease caused by the bacterium, Brucella suis. The bacterium can be transmitted to humans and is known as undulant fever, causing flu-like symptoms in humans. Other diseases of feral hogs include pseudorabies, tuberculosis, bubonic plague, tularemia, hog cholera, foot and mouth disease, and anthrax. In general, diseases from feral hogs do not pose a significant threat to humans. However, some diseases can be transmitted to livestock and wildlife. It is important to keep all livestock vaccinated, especially where large feral hog populations are concentrated (TPWD 2007b).Prohibited Lists
TPWD (2007b) considers feral hogs nuisance animals and does not support their introduction. Feral hogs are not classified as game animals. However, a hunting license is required to hunt them. The Texas Animal Health Commission has enacted regulations requiring all feral hogs in Texas to be tested and certified to be disease free before being released into the wild for whatever purposes. If stocking is desired, only castrated males (barrows) should be considered. Feral hogs may be legally transported to slaughter or livestock sale for slaughter.Introduction Pathways
Hogs were introduced to Texas over 300 years ago by Spanish settlers. European wild boars were first brought into Texas in the 1930s for hunting. These hogs escaped and became free-ranging (feral), and cross bred with European boars. Feral hogs are introduced to new areas through natural dispersal and through the escape of domesticated hogs from free-range commercial ranches (TPWD 2007b).Geographic Distribution
The feral hog inhabits most of Texas, with the highest densities in east, south and central Texas. Feral hogs occur in all 5 counties of the Lower Galveston Bay watershed (Brazoria, Chambers, Harris, Galveston, and Liberty) (TPWD 2007b).Specific Primary Habitats
In Texas, feral hogs are found in a variety of habitats. They are often found in areas associated with dense vegetative cover and water such as wet pine forests, bottomlands (rivers, creeks, etc.), and scrub/shrub habitats. They can also be found near food supplements such as nut producing trees or agricultural areas (TPWD 2007b).Ecological, Economic, or Social Impact
Feral hogs impact ecosystems through habitat destruction and competition for food. The rooting and wallowing behavior of pigs is disruptive to soil, vegetation, and soil invertebrate species. Not only do feral hogs directly compete with livestock and wildlife species for food, their rooting behavior also damages livestock feeding and watering stations (TPWD 2007b).Physical Description
Feral hogs often appear much the same as domestic hogs, depending upon the individual's amount of crossbreeding with the European boar. However, feral hogs are more muscular than domestic hogs, and have very little fat. Feral hogs are usually black, brown or reddish in color, with stiff bristly hairs. Feral hogs can reach a height of about 3 feet tall at the shoulder and weigh from 100-400 pounds. They have four, long, razor-sharp tusks (two on top, two on bottom) (TPWD 2007b; ISSG 2008c).Reproduction Characteristics
Feral hogs can begin breeding at about 8-10 months of age. Gestation is 115 days with an average litter size of 4-6. They usually only produce one littler per year, although are capable of producing two (TPWD 2007b).Feeding
Pigs are opportunistic omnivores. They prefer to eat acorns and agricultural crops such as corn, rice, wheat soybeans, peanuts, etc., although they will also consume invertebrates, reptiles, amphibians, carrion, small mammals, and birds. They will also eat grasses, roots, tubers, fruits, bulbs and mushrooms (TPWD 2007b; ISSG 2008c).Control
Hunting and trapping are common control techniques for the feral hog. In Texas there is an open season on feral hogs, although a hunting license is required to hunt them (TPWD 2007b).Lists
This species belongs to the following lists:
Images
To view a larger version of an image, click on the thumbnail. Feral hog (Sus scrofa). Photo courtesy of James Dowling-Healey, Animal Diversity Web, University of Michigan Museum of Zoology. |
 Wild boar (Sus scrofa). Photo courtesy of Tanya Dewey, Animal Diversity Web, University of Michigan Museum of Zoology. |
 Damage caused by Sus scrofa. Photo courtesy of Billy Higginbotham, Texas Agrilife Extension Service, Bugwood.org. |