Feral Swine (Sus scrofa)


Biology  |  Impacts  |  Signs of Feral Swine  |  Management  |  Reporting

Introduction

Feral swine, also known as feral pigs or wild boars, is a designation that can be applied to introduced Eurasian boars, escaped or released domestic pigs, and cross-breeds of the two. Eurasian boars were introduced to North America as early as 1539 as domestic pigs; additional introductions of other wild Eurasian boar races for hunting occurred through the1800’s and 1900’s.

New York populations of feral swine have most likely emerged from escaped and abandoned Eurasian boars kept in captivity and at hunting preserves. Feral swine crossbreed readily with domestic pigs, which has resulted in a wide range of coat colors and body shapes.  Many look like typical wild boars, while others may be hard to distinguish from domestic pigs.

Known breeding populations of feral swine in NY (2011) include northwest Cortland, southwest Onondaga, and southern Tioga counties. Pennsylvania also has well established populations in 18 or more counties.  Swine may be seen in several Southern Tier border counties with Pennsylvania. Feral hogs have also been observed in a few upstate counties associated with hunting preserves.

 

2010 Feral Swine populations in New York and surrounding areas (USDA-APHIS)

Biology

Feral pigs can breed at any time with a gestation of 115 days. A female is sexually mature at 1 year of age. Litter sizes range from 1-8 piglets; sows aggressively protect their young. Due to their hardiness and ability to adapt to a wide range of weather conditions and food sources, feral swine can triple their population in a year.

Sows average 110 pounds and boars 130 pounds, but can reach up to 400 pounds. They can be spotted, belted, or striped, entirely brown or domestic looking. Their razor sharp tusks can be 5 inches long before breaking or wearing down. Swine use their tusks to defend themselves and to establish dominance. In NY, the adults have few predators to control herd size.

Impacts

Feral swine (Sus scrofa) have a list of environmental, agricultural and human impacts including:

  • Tearing up farm and forest land as they root and wallow, destroying acres of agricultural land and crops in just a few days.
  • Carrying diseases transmittable to domestic pigs and humans, including swine brucellosis, pseudo-rabies, trichinosis and leptospirosis.
  • Competing with wildlife for food.
  • Fouling water supplies.
  • Feeding on fawns, ground nesting birds and reptiles, and even young livestock.
  • Destroying wildlife habitat and sensitive natural areas
  • Contributing to erosion and water quality issues.
  • Serving as a highway hazard; swine eyes do not reflect in light at night.
  • Displaying aggressiveness toward humans with the potential to cause harm.

Feral swine (Photo: Billy Higginbotham, Texas AgriLife Extension Service, Bugwood.org )

 

Damage to suburban yard caused by feral swine. (Photo: Billy Higginbotham, Texas AgriLife Extension Service, Bugwood.org)

Signs of Feral Swine

Feral swine are nocturnal; rooting and wallowing in fields and forests, eating crops and hunting. They can decimate acres of fields and gardens every night. Their rooting furrows, 2 to 8” deep, leave a “plowed” look to the landscape.

Their tracks and impressions of their coarse hair can be seen at wallowing holes, creeks and mud holes. After wallowing, which can destroy habitat, they often rub the mud onto nearby trees. Swine tracks are similar to deer tracks, but more rounded. Swine scat can resemble deer, dog and human scat.

Tracks: Deer, left, feral swine, right (Credit: Internet Center for Wildlife Damage Management, http://icwdm.org)

Management

 In New York, anyone with a small game license may hunt and keep feral swine year round with no limit. To prevent the spread of disease, wear plastic or rubber gloves while dressing the animal, and bury the offal. Do not feed raw meats or organs to pets or livestock and thoroughly cook the meat before consuming.

Feral swine may be excluded from gardens and domestic hog pens with very heavy duty fencing, but since they can burrow, fencing should be monitored. Domestic swine should be securely enclosed.

Shooting can be used to remove one or two feral hogs, but trapping is recommended for removing family groups. Specially-designed corral traps with heavy metal fencing and mechanical doors are needed to capture free-ranging swine.

Adult feral wine (Photo: The Nature Conservancy Archive, The Nature Conservancy, Bugwood.org)

Reporting

If you see, shoot, or trap feral swine please report it to your regional NYS DEC Wildlife office http://www.dec.ny.gov/about/50230.html. It is important that natural resource managers know where the swine are.

Feral swine are a threat to New York’s landscape and agriculture. They can cause an immense amount of damage in a short period of time and can transmit disease. Please do not intentionally release swine into the wild for hunting and keep an eye out for escaped domestic pigs. Eradication of feral swine is important.

 

 

Resources

Curtis, Paul, Associate Professor, Extension Wildlife Specialist, Cornell University. E-mail conversation. August 6, 2011.

Perry, Adam. Wildlife Biologist, New York State Department of Conservation. Phone and e-mail conversation. August 3 and 4, 2011

USDA. 2010. 2010 Status of Feral Swine in New York State. USDA, APHIS-Wildlife Services, Castleton, NY. 19pp.

 

Educational Materials

Printable Feral Swine Factsheet- NYIS- CCE 2011

Feral Hogs. Missouri Department of Conservation Invasive Species Management fact sheet.

 

The Feral Hogs Community of Practice at eXtension.org.  This is a fantastic collaboration representing 23 states. Feral Hogs Community of Practice is a great resource for County Extension Agents, natural resource professionals, landowners, and managers.

You will find the following items on our web-site:

  • Information on feral hog webinars
  • 103 Answers to Frequently Asked Questions
  • 49 feral hog articles
  • 6 feral hog videos
  • Social media on feral hogs via their FaceBook page
  • Feral hog news updates, and
  • an option to send questions via Ask the Expert

 

 

Links

USDA, APHIS, Wildlife Services New York 2012 Feral Swine Management Report

Internet Center for Wildlife Damage Management: Wild Pigs: http://icwdm.org/handbook/mammals/wildpigs.asp

NYS DEC Feral Swine Profile. http://www.dec.ny.gov/animals/70843.html

USDA APHIS Widlife Damage Management- Feral Swine: http://www.aphis.usda.gov/wildlife_damage/feral_swine/index.shtml

USDA National Invasive Species Information Center- Wild Boar: http://www.invasivespeciesinfo.gov/animals/wildboar.shtml

Wild Pig Info. Mississippi State University: http://wildpiginfo.msstate.edu/index.html
                       Including the video series "A Pickup Load of Pigs- the Feral Swine Pandemic"

Feral Hogs in Missouri: Damage Prevention and Control- http://extension.missouri.edu/p/G9457

Missouri Department of Conservation Invasive Species Management.  http://mdc.mo.gov/landwater-care/invasive-species/invasive-animal-management/feral-hog-control