Part III: Conservation and Management316
through biological dispersal across international boundaries
(Figure 29.1).
Argentina and Brazil contributed the most for the total range
of invasion in the South American continent, 6.5 per cent and
3.6 per cent, respectively (Table 29.1). Although Argentina has
faced the longest invasion process (at least 102 years in nature
according to Navas 1987), which could explain the wider dis-
tribution, Chile (66 years; Skewes & Jaksic 2015) and Uruguay
(90 years; Daciuk 1978; Herrero & Luco 2003) have had more
time to spread the species than has Brazil (Figure 29.3). There
was one isolated case of two invaded Brazilian municipalities
in 1965, but the wave of invasion in Brazil effectively started
in the mid-90s, with six different municipalities in 1995 and a
rapid increase to 489 in 2016 (IBAMA 1995, 2002, 2004, 2005;
Frankenberg 2005; Deberdt & Scherer 2007; Pedrosa et al. 2015).
The wave of invasion in Brazil was somehow faster than other
countries with potential to spread across the continent.
The speed of invasion was different between countries, but
its range is still increasing where possible. In Uruguay, for exam-
ple, the invasion reached almost its maximum, with less than
one percent of the country’s areas free of wild boar, as these were
unsuitable habitats for the species and isolated areas, such as
rocks, swamplands, and islands (Figure 29.1, Table 29.1, Table
29.2). Moreover, these five countries connected by wild boar
populations tried different kinds of initiatives to control the
invasion (Navas 1987; Deberdt & Scherer 2007; Ghione et al.
2008; Skewes & Jaksic 2015), but they had difficulties developing
effective national policies; otherwise, the invasion would have
been under control.
The cross-border connections between the populations
increased the challenge of controlling the species in the South
American countries, in addition to imposing international coop-
eration between them due to constant reinvasion. For example,
the eradication of the wild populations in the extreme south of
Brazil is a difficult initiative to be undertaken by Brazil alone
without the cooperation of Uruguay. This situation is reciprocal
and finds parallels in every region in South America where wildFigure 29.3 Brazilian municipalities with confirmed wild populations of
wild boar Sus scrofa between 1965 and 2016. References: a (IBAMA 1995);
b (Frankenberg 2005); c (IBAMA 2002); d (IBAMA 2004); e (IBAMA 2005);
f (Deberdt & Scherer 2007) ; g (Pedrosa et al. 2015); h (current review).boar have invaded, such as the borders between Argentina and
Chile and between Brazil and Paraguay.Wild Boar Invasion According to Ecosystems
Regarding ecosystems rather than political borders, the wild
boar invaded nine biomes and 25 ecosystems in the Neotropical
realm (Table 29.2). The most invaded biome was the Temperate
Grasslands, Savannas & Shrublands (TGSS), with 58 per cent of
the area covered by the current range of wild boar. Consequently,
TGSS had three of the five most likely invaded ecosystems
(>70 per cent of the area within the wild boar’s range): Humid
Pampas (96 per cent), Espinal (80 per cent), and Low Monte
(61 per cent). The other top five invaded ecosystems (>70 per cent)
were Paraná flooded savanna (86 per cent) and the Uruguayan
savanna (75 per cent).
The most invaded ecosystem had good climate-matching, as
the areas occupied were similar to their native ranges (Novillo &
Ojeda 2008; Ojeda et al. 2010; Ballari et al. 2015). Nevertheless,
that could be a biased interpretation based only on the range
within the oldest and the widest region under invasion in SouthTable 29.1 Countries and protected areas invaded by wild boar (Sus scrofa); ranges overlapping the total original geographical distribution of native peccaries
Pecari tajacu and Ta yassu p e ca r i; and ranges overlapping the areas where they are considered extinct in South America.Political
territoryaInvasion Protected areasb Peccary range overlapc
Range
(km^2 )Country
(%)Continent
(%)Potential Confirmed Original (%) Extinct (%)
n % n % P. tajacu T. pecari P. tajacu T. pecari
Argentina 1 199 665 41.9 6.5 133 36.5 44 12.1 34.4 20.3 25.5 20.3
Brazil 652 763 7.5 3.6 265 15.3 41 2.4 7.3 7.3 0.8 1.3
Chile 68 707 8.9 0.4 34 20.4 6 3.6 – – – –
Paraguay 29 464 7.3 0.2 12 36.4 0 0 7.3 7.3 – 1.1
Uruguay 176 690 99.7 1.0 15 100.0 0 0 – – – –
South
America2 127 289 – 11.6 459 13.0 91 2.6 6.9 5.8 2.2 1.8aPolitical areas based on the World and Brazilian Administrative Divisions (IBGE 2015; ESRI 2016). Divergences of 0–1.5 per cent for each country’s official area
due to geographic projections.
bAll categories of Protected Areas in IUCN and UNEP-WCMC (2016).
cPeccary distribution according to IUCN (2010)..031Downloaded from https://www.cambridge.org/core. Faculty of Classics, University of Cambridge, on 04 Dec 2017 at 12:52:31