Monday, August 23, 2010

Hog Wild!

During the past year, wild hogs (Sus scrofa) have become on increasing problem around the boardwalk at the Audubon Center at the Francis Beidler Forest.  Not only have the animals been seen from the boardwalk by staff and visitors, the habitat often looks as though a rototiller-armed platoon of gardeners has assaulted through the area.  Beyond the rooted earth, an unknown number of ground-nesting bird eggs, turtle eggs, and amphibians may have been consumed by the non-native, omnivorous hogs.  The serious threat to the old-growth habitat within eyesight of the boardwalk has forced us to aggressively seek solutions to the invasion of wild hogs.

Last Wednesday, we attended workshop at the Clemson Extension Service's Columbia-area Sandhill Research and Education Center on the topic "Managing Wild Hog Damage in South Carolina."  The workshop's title is somewhat misleading as the wild hog problem is not simply a South Carolina issue or a southeast United States issue, but it is a global issue.  Not all habitats are suitable for wild hog survival, but the species exists on all continents except Antarctica.  It is a global issue not only due to critical habitat destruction, negative impacts on native wildlife, and water quality degradation, but also due to the real and potential economic losses.  Economic losses include crop damage and losses (consumed), failure of reforestation (seedlings consumed), predation of livestock (lambs and calves), resource competition with game species, and damage to suburban landscapes. Finally, there is the threat of disease transmission to the domestic hog stock or to humans. This threat can lead to loss of livestock and/or orders for pork by consumers.  Diseases and risks associated with wild hogs include pseudorabies, swine brucellosis, classical swine fever, African swine fever, bovine tuberculosis, influenza, anthrax, tularemia, West Nile virus, E. coli, Salmonella, trichinosis, streptococcus, ticks, fleas, lice, and intestinal parasites.  Yikes!

The workshop's plethora of experts covered the following topics:  history and ecology of wild hogs in the Southeast; diseases and safe handling techniques of wild hogs; negative impacts of wild hogs; South Carolina hog harvest trends; research and management update; state regulations of wild hogs; management techniques to reduce wild hog populations; and demonstrations of various hog traps.  Folks, it does not look good for South Carolina's native wildlife and habitats.

Hogs are not native to this continent.  European settlers brought hogs, which had long-since been domesticated from the Eurasian Wild Boar population.  Some of these domesticated hogs were released to forage or escaped on their own into the wild to become feral hogs.  In the early 1900s, pure Eurasian Wild Boars escaped a hunting enclosure on Hoover Bald, NC and began to breed with the feral hog population producing the hybridized wild hogs now found throughout the Southeast and within 45 of 50 states in the United States.

Although wild hogs will eat almost anything, they have habitat requirements that restrict their ranges.  Wild hogs need year-round access to food, water, shade, and escape cover.  Water and shade are critical for hogs in order to regulate their body temperature.  Wallowing in wetland areas degrades water quality by destroying the habitat and associated wildlife, increasing sedimentation and soil erosion, and introducing fecal material into the water system.  In our state, the hotspots include swamps within the Coastal Plain, especially the Congraree River (Congaree National Park) system, the Wateree River system, the Pee Dee River system, and the Edisto River system, which includes Four Holes Swamp and the Francis Beidler Forest.

Wild hogs reach sexual maturity between three and six months, breed year-round (2-3 litters per year), and have an average litter size of six (can be as many as 16).  With those reproduction numbers, killing 7 of 10 hogs would only maintain the population at its current level.  With hogs favoring swampy areas with ample escape cover, trapping multiple hogs at a time is the most effective management technique, but hunting and law enforcement are also required.  Wild hogs have few natural predators, they are alert, and they quickly learn to avoid human threats and traps, which have been ineffective or which have captured only a few of the sounder (group name based on the grunts used to keep the group together in poor visibility). 

Unfortunately, the main deterrent to successful wild hog management and the preservation of our native wildlife and habitat is the illegal practice of releasing hogs (domestic or wild-caught elsewhere) into the wild for the purpose of hunting.  Act 211-2010, 50-16-25 SC Code of Laws states that, "It is unlawful to possess, buy, sell, offer for sale, transfer, release or transport for the purpose of release a hog into the wild."  If you know of any such violation, please contact your local Department of Natural Resources officer.

Don't allow our water quality, habitat, and wildlife to be destroyed by non-native hogs!

Images by Mark Musselman

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