Part III: Conservation and Management304
physical maturity in the wild seldom achieve such large weights.
Recent reports of harvested North American wild pigs exceed-
ing 450 kg (e.g. ‘Hogzilla’, ‘Hog Kong’, or ‘Monster Pig’) have
turned out to be captive-reared males that either were released
or escaped into the wild before being killed. The average adult
body mass of wild pigs in North America is approximately
85 kg (70–75 kg for adult females and 95–100 kg for adult males).
Some insular populations of wild pigs are substantially smaller
than this, with adult animals averaging around 40 kg. Typically
maximum body masses observed in wild pig populations on
the continent do not exceed 200–250 kg. However, exceptional
male specimens have been reported to exceed 300 kg (Mayer &
Brisbin 2008, 2009).
External dimensions – Similar to total body mass, the exter-
nal dimensions of North American wild pigs are highly vari-
able. A summary of seven external body dimensions from 325
adult North American wild pigs is provided in Table 28.2. As in
other wild populations of this species, males tend to be larger
than females. Sweeney (1970), Barrett (1971), and Belden and
Frankenberger (1979) found significant differences between the
sexes in the body dimensions of adult wild pigs from different
locations in the USA with the males being larger. However, some
studies (e.g. Henry 1970; Brisbin et al. 1977) found these differ-
ences not to be significant between the sexes in adult animals.
The best dimensions to use for distinguishing between the three
general types of North American wild pigs were snout and hind
foot lengths (Mayer & Brisbin 1993).
Coat coloration patterns – The coat coloration observed
among North American populations of wild pigs varies from
uniform colours to mixed patterns. The simplest of these is the
uniform coloration. This can be expressed as any of the basic col-
ours (i.e. black/eumelanin, red–brown/pheomelanin or white/
absence of melanin) found in this species. The next pattern is
spotted or mottled. This is a mixed pattern of two or more of the
basic colours and is highly variable. The most unique or unusual
is the belted or shoulder band pattern, which is often referred to
as a ‘Hampshire’ band after the domestic breed most recognized
for this specific coloration pattern. All of the aforementioned
patterns have been observed in both feral pigs and hybrids.
The presence of light points (i.e. white coloration on the distalFigure 28.4 Representative mean variation (based on multivariate cranial
analyses; Mayer & Brisbin 2008) exhibited in the skulls of adult male North
American wild pigs (Sus scrofa). The straight or curved lines above each cranium
illustrate the dorsal profile and the tilted vertical lines to the left of each
cranium illustrate the angle of the occipital wall (photos by John J. Mayer).Table 28.1 Summary of five skull measurements (in mm) of 191 adult wild pigs from 57 populations in North America. Data were segregated by sex. These
measurements are defined in Mayer and Brisbin (2008).Measurement (in mm) Sex N Mean Observed range SD
Condylobasal length Female 71 282.6 233–351 21.5
Male 120 303.8 246–388 26.3
Occipitonasal length Female 71 285.7 235–371 25.8
Male 120 308.2 249–409 29.6
Zygomatic breadth Female 71 139.5 114–167 12.1
Male 120 151.7 116–230 18.2
Mandibular length Female 71 221.7 119–281 21.6
Male 120 244.6 198–324 24.8
Posterior mandibular Female 71 121.7 97–152 12.4
width Male 120 135.4 104–196 17.4.03012:52:20