Chapter 28: Introduced wild pigs in North America301
hunting preserves (Gipson et al. 1998; Mayer & Brisbin 2009;
Hamrick et al. 2011). This increase can be directly attributed to
the growing popularity of these pigs as a game species. Back in
the 1950s to the 1970s, several US states were promoting these
animals as huntable game, which included the active stocking of
wild pigs into a number of locations. A number of these states
gave these animals legal game status, which variously included
the implementation of licence/tag requirements, harvest sea-
sons, bag limits, and weapons restrictions. These promotional
efforts were very successful among the country’s sport-hunting
populace, with wild pigs becoming the second most popular
big game animal in the USA, second only to the white-tailed
deer (Odocoileus virginianus) in numbers harvested every year
(Kaufman et al. 2004).
The history of wild pigs in Canada differs from that of the
rest of North America. Prior to the late twentieth century, the
only free-ranging pigs in Canada were found on Sable Island,
Nova Scotia; however, that population died out by the late
1700s (Lever 1985). A more recent report on supposed ‘feral
pigs’ in Canada by Smith and Hawkes (1978) actually involved
a captive population on Robert’s Island, Nova Scotia. Then,
beginning in the 1980s, the Ministries of Agriculture in sev-
eral Canadian provinces began promoting wild boar farming
as part of a livestock diversification programme. The goal of
these endeavours was to focus on three main markets: exotic/
specialty meats, breeding/production stock, and commer-
cial fenced hunting operations (Harris et al. 2001). The initial
breeding stock used in these programmes consisted of geneti-
cally pure Eurasian wild boar that were obtained from sources
in Great Britain, Poland, Germany, and Sweden (Brook & van
Beest 2014). On a few farms, the pure wild boar were hybrid-
ized with domestic swine to increase reproduction. At the peak
there were hundreds of producers across southern Canada.
However, these markets were not as lucrative as initially pro-
jected. Not realizing the necessary return on investment to stay
in business, some producers killed off their herds while others
simply released their stock to survive on their own (Fritze 2002).
Initially thought to be incapable of surviving the Canadian
winters if they escaped (T. Whiting, Manitoba Agriculture &
Food, personal communication), the now free-ranging wild
boar have thrived and spread. In 1999, 25–30 wild boar even
spread south from Manitoba into North Dakota, prompting
eradication efforts on both sides of the border (Dokken 1999).
In the 2000s, established populations with significant numbers
of wild boar or hybrids were reported in Alberta, Manitoba,
and Saskatchewan (Brook & van Beest 2014). Between 2013 and
2014 reports were also received of sightings in eastern Ontario,
western Quebec and southern British Columbia (BCMFLNRO
2014; Bostelaar 2014).
Populations of wild pigs have been present in Mexico since
colonial times. Most of these were feral animals established as a
result of the widespread free-ranging of domestic pigs, a prac-
tice which still exists in Mexico today (Lever 1985; Copado et al.
2004). There has also been the active stocking of the Eurasian
wild boar for sport-hunting purposes (Weber 1995). More
recently, wild pigs along the border with the USA have dispersed
south into Mexico (AFP 2011).
As already detailed, the early history of wild pigs in the West
Indies pre-dates that of most of the rest of North America. The
West Indies encompasses both the Caribbean islands, includ-
ing the Greater, Lesser and Leeward Antilles, the Lucayan
Archipelago, including the Bahamas and Turks and Caicos
Islands, and Bermuda. Following the initial introduction by
Columbus in 1493, pigs were subsequently introduced by other
European explorers and colonists onto most islands within this
region by the 1700s (Husson 1960; Wiewandt 1977; NPS 2003).
This was in part done to provide food for subsequent voyages or
for shipwrecked sailors who might end up stranded on some of
these islands (Wiewandt 1977; Elliott 1977). Such island releases
resulted in these domestic animals going wild. However, a large
number of these wild pig populations had disappeared by the
early 1900s, land clearing/deforestation and over-hunting being
identified as the apparent cause. More recently, management
efforts have been implemented to reduce the numbers of wild
pigs on some islands in the West Indies to either control disease
outbreaks (e.g. African swine fever on Haiti) or the damage being
done by these animals (Wiewandt 1977; Angier 1984; NPS 2003).
There is no documentation of any introductions of Eurasian wild
boar onto any of the islands within the West Indies.Current Status
Wild pigs are the most abundant and widespread free-ranging
large non-native ungulate found in North America (Figure 28.2).
Populations of these animals appear to be well established and
continuing to expand in distribution and numbers on this conti-
nent at this time (Mayer & Brisbin 2008, 2009).
In the continental United States wild pig populations are cur-
rently reported to be established in 34 states (NFSMS 2015; J. L.
Corn, SCWDS, personal communication). ‘Established’ popula-
tions are defined as those being present for two or more years
and where there is evidence of reproduction (J. L. Corn, SCWDS,
personal communication). There are 13 additional states that
have reported the recent presence of these animals. The status
in these latter states would entail very localized numbers of wild
pigs stemming from either recently released animals or escaped
individuals from private or commercial fenced enclosures. Some
of these occurrences represent upwards of 100 or more animals,
while others merely note the reported presence of wild pigs (as
low as a sighting of a single animal) in those states. The fate of this
latter category of wild pigs may be temporary in nature at best,
with several of these states reporting that all of the free-ranging
pigs within their state’s boundaries having been eliminated. The
most recent national population estimates for wild pigs in the
USA is approx. 6 million animals with a range of 4–11 million.
Collectively, 99 percent of that total estimate was from the states
of Alabama, Arkansas, California, Florida, Georgia, Louisiana,
Mississippi, Oklahoma, South Carolina, and Texas (Mayer 2014).
Populations of wild pigs in Canada are reported to be
found in six provinces, including Alberta, British Columbia,
Manitoba, Ontario, Quebec, and Saskatchewan (BCMFLNRO
2014; Bostelaar 2014; Brook & van Beest 2014). No formal
nation wide population estimate of these animals in Canada
has been conducted to date; however, most recent estimates vary.03012:52:20