Chapter 26: Conservation of wild pigs and peccaries285
endangered because they are confined to the island of Mindoro
in the central Philippines (Meijaard et al. 2011; Chapter 16 in
this book). Collared peccaries appear to be less vulnerable to
local extinctions for several reasons. For example, they have
greater physiological tolerance of environmental extremes, e.g.
temperature and moisture (Sowls 1984). Another characteristic
which seems to reduce the vulnerability of collared peccaries
and other species such as wild boar (Eurasian regions) or red
river hog (from tropical Africa) to local extinction is their ability
to adjust their ranging patterns to local conditions, e.g. habitats,
food resources, and competitors.
Species are more vulnerable when they are specialized in
their resource requirements; for the pygmy hogs, when their
preferred grasses are burned, their habitat becomes suboptimal
without their taller preferred grass species (Bell & Oliver 1992).
Other endangered species such as the Javan warty pig require
habitats below 800 m a.s.l. because they are possibly intolerant
of lower temperatures (Meijaard et al. 2011).
The intricate relationships between habitat carrying capac-
ity and habitat size, and extrinsic pressures such as hunting, are
well demonstrated in the wild boar. Sus scrofa stands out in its
ability to switch between r and K strategies, depending on local
availability of resources. When conditions are favourable the
species can increase in numbers quite rapidly (Meijaard et al.
2011; Massei et al. 2015; see also Chapter 21 in this book).
Ecological Roles and Importance as a
Conservation Tool
The status of peccary populations in a landscape is an indica-
tor of forest health because the species plays important ecologi-
cal roles. All three peccary species benefit regional biodiversity
because they are wide-ranging, use a diversity of habitats, are
vulnerable to human alterations of the landscape, and play
important ecological roles in the ecosystem as seed predators
and dispersers, as ecosystem engineers, and as prey of puma and
jaguar (Keuroghlian & Eaton 2009; Reyna-Hurtado et al. 2009;
Beck et al. 2010; Cavalcanti & Gese 2010; Altrichter et al. 2012;
Keuroghlian et al. 2012, 2015). In large protected areas such
as the Iguaçu National Park (INP) in southern Brazil, white-
lipped peccaries have become locally extinct due to hunting
(Azevedo & Conforti 2008), and consequently there has been an
80 per cent population decline in the jaguar population (Morato
et al. 2013). Studies show that peccaries are ecosystem engineers
responsible for significant soil, litter, and vegetation alterations,
which may have cascading effects in tropical forests (Fragoso
1998; Painter 1998; Silman et al. 2003; Beck 2005; Keuroghlian &
Eaton 2009; Beck et al. 2010; Reider et al. 2013; Galetti et al.
2015a,b). In the Amazon, white-lipped peccaries are considered
to be ecosystem engineers because the wallows they form make
the water last into the dry season more than natural depressions.
According to Beck et al. (2010), these wallows support repro-
ductive activities for many amphibians and increase the anuran
biodiversity of forests, and without peccaries, wallow-breeding
anurans would not have access to important reproductive habi-
tat. Reider et al. (2013) showed that the peccaries’ impact on the
physical structure of the leaf litter promoted greater recruitment
of juvenile anurans. Galetti et al. (2015a,b) demonstrated that
white-lipped peccaries control rodent seed predation, because in
their absence, rodents either increased in population size due to
reduced competition with large mammals or just increased their
predation activity. Consequently, seed predation of the palm
(Euterpe edulis) increased 4.9 times more by rodents (Galetti
et al. 2015a,b). These shifts showed that there are potential con-
sequences for plant–animal interactions and plant recruitment
that could impact many other species dependent on this palm.
Wild pigs are an important prey for large carnivores such as
lions, tigers, and leopards across their distribution range. While
foraging, wild pigs modify soils while searching for roots, tubers
or insects, and by wallowing in ephemeral ponds (Meijaard et al.
2011; Reyna-Hurtado 2015; Chapter 36 in this book). Forest
hogs of Africa are heavy grazers and browsers of several herba-
ceous species and keep them at low densities in the forest clear-
ings and maintain the diversity of herbaceous species.
This activity conserves such clearings that are important
for other species, such as bushpigs (Potamochoerus larvatus)
(Reyna-Hurtado et al. 2014). Red river hogs (P. porcus) also
function as seed predators, selectively feeding on seeds and pre-
venting their germination, which influences the plant diversity
of the forest (Beaune et al. 2012; Leslie & Huffman 2015; see
also Chapter 13 in this book). Similarly, bearded pigs in Borneo
are a major factor in tree seedling survival when mast-fruiting
causes a super-abundance of fruit, resulting in the congregation
of large numbers of seed predators feeding on these fruits with
their predation pressure ultimately deciding whether any seeds
survive to germinate (Curran & Leighton 2000).
Finally, wild pigs can play a role in diseases transmission; for
example, diseases such as African swine fever as has been deter-
mined for common warthogs (Phacochoerus africanus) and red
river hogs (Leslie & Huffman 2015) (also see Chapter 35). There
are many more diseases that can be transmitted among wild and
domestic suids and tayassuids (Herrera et al. 2005, 2008; Jori &
Bastos 2009; Freitas et al. 2010). A recent account on the topic
can be found in Chapter 35, where classical swine fever, African
swine fever, Aujeszky’s disease (AD), and porcine brucellosis
are mentioned as diseases enzootic in many wild and feral pig
populations worldwide and representing a serious challenge to
the pig farming industry. In addition, many other contagious
diseases are potentially shared between wild and domestic
swine over the world including porcine circovirus, porcine par-
vovirus, mycoplasmas, influenza, porcine reproductive and res-
piratory syndrome virus (Jori & Bastos 2009; Meng et al. 2009;
Chapter 35). Wild pigs are also hosts of several species of par-
asites. One study about parasites species using faecal samples
from forest hog, bushpigs and domestic pigs in Kibale National
Park (A. Tumukunde, personal communication) determined
that overall, 92.8 per cent of the animals were infected with at
least one parasite species, with 61.9 per cent of animals being
multi-infected.Conservation Implications
Neither pigs nor peccaries feature very prominently on the
global wildlife conservation agenda. Unlike great apes, large
cats, or other charismatic species they lack the ‘cuddly’ factor.02812:52:18