Ecology, Conservation and Management of Wild Pigs and Peccaries

Chapter 28: Introduced wild pigs in North America

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portions of the snout, ears, legs, and tail) can be observed with
any of the aforementioned patterns. The most complex pattern
observed in wild pigs is the adult wild/grizzled pattern exhib-
ited by Eurasian wild boar and some hybrids with feral pigs.
Some wild pigs exhibit a striped juvenile pattern, which can be
found in any of the three types of wild pig populations (Mayer &
Brisbin 1993, 2008, 2009).
The frequency of coat coloration patterns varies among
wild pig populations. Solid black is often cited as the most com-
mon pattern (Sweeney et al. 2003). However, other populations
have spotted coloration as the most common pattern observed
(Mayer et al. 1989). Based on a sample of 4014 wild pigs from
13 populations in the USA, the coat coloration percent break-
down was as follows: all black – 32.0 per cent; all white – 6.1 per
cent; all red/brown – 4.7 per cent; spotted – 50.6 per cent; belted

• 2.8 per cent; wild/grizzled – 3.5 per cent; and miscellaneous


• 0.3 per cent. ‘Miscellaneous’ includes infrequent or rare colora-
  tion patterns such as blue or grey roans (Mayer & Brisbin 2009).
  Unique physical characters – Two uncommon features of
  note observed in wild pigs in North America are syndactylous
  (a.k.a. ‘mule-footed’) hooves and neck wattles (Figure 28.5). The
  presence of these unusual structures is neither widespread nor
  frequently observed even where they are known to occur. In
  a few locations, both characters are found to occur within the
  same population (Mayer & Brisbin 1993, 2008, 2009).

Impact

As elsewhere, wild pigs in North America do a lot of damage to
both the natural and human environments, with the magnitude
of this damage being rivalled only by the diversity of impacts
observed. Such damage on this continent is nothing new, hav-
ing been reported to occur as far back as the 1500s in the West
Indies (Zadik 2005) and the 1600s on the North American
mainland (Conover 2007). The various impacts caused by these
animals have been described in detail elsewhere (e.g. Mayer &
Brisbin 2009; West et  al. 2009; Barrios-Garcia & Ballari 2012;

Table 28.2 External body dimensions of 325 adult wild pigs from seven populations in North America separated by sex. These measurements are defined in

Mayer and Brisbin (1993, 2008).

Measurement (in mm) Sex N Mean Observed range SD

Head–body length Female 157 1308.9 840–1580 111.5

Male 168 1382.5 950–2041 138.6

Tail length Female 157 297.5 171–395 39.6

Male 168 313.7 100–422 58.2

Hind foot length Female 157 267.9 185–325 19.6

Male 168 284.0 200–388 23.5

Ear length Female 157 154.5 105–204 17.5

Male 168 162.8 100–250 22.2

Shoulder height Female 157 692.4 515–847 49.5

Male 168 751.1 535–1092 78.5

Snout length Female 157 221.7 155–274 20.9

Male 168 237.9 160–298 23.7

Figure 28.5 Examples of North American wild pigs (Sus scrofa) exhibiting a

syndactylous foot (upper image) and neck wattles (lower image) (photos by

John J. Mayer).

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