Ecology, Conservation and Management of Wild Pigs and Peccaries

Chapter 35: Disease transmission at the interface between wild and domestic Suiform species

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Telemetry

Global positioning system (GPS) technology has been widely
used to assess wild animal movement worldwide. GPS loca-
tions can be used to study interactions between wild pigs and
livestock in the framework of disease transmission and the sub-
sequent implementation of targeted management strategies.
Estimating direct contact between sympatric species requires
fitting animals concurrently with GPS collars programmed
with the same schedule so that fixes are taken simultaneously
(Latham & Latham 2015). Co-occurrence from GPS data
between species can also be studied by using cluster function
to quantify spatiotemporal distances between pairs against ran-
domness (Dohna et al. 2014). Other indices have been devel-
oped to address dynamic interactions, examine attraction/
avoidance behaviour or cohesiveness of movement between
two individuals (Long et al. 2014; Pepin et al. 2015). Finally, the
recent development of proximity loggers allows the emission
of a different signal when two radio-tagged individuals move
within a defined close range, allowing the spatial and tempo-
ral monitoring of contacts between two specific individuals in
proximity (Cowie et al. 2016).
Indirect contacts can be recorded from raw GPS data, when
fixes indicate subsequent use of the same locations in a time-
lapse compatible with the survival time of the pathogen. GPS
data may also be used to estimate overlap between individual
home ranges (HR) or the habitat use and selection of the moni-
tored animals, by for instance, computing the percentage of
overlapping HR between two animals (Barasona et  al. 2014).
When livestock is kept in confined areas (pastures, farm build-
ing), indirect contact can also be deduced by the incursion of
wild animals in those areas (Wyckoff et  al. 2009; Cowie et  al.
2016). Finally, spatial hotspots for interactions can be identi-
fied by using resource selection functions (Barasona et al. 2014)
or by weighing landscape items with the contact rates or home
range overlap indexes (Kjaer et al. 2008).

Camera Traps

A camera trap is an automated camera with infrared motion

or heat sensor, allowing pictures or video footage to be taken

whenever movement or an animal is detected within the detec-

tion zone of the camera (Trolliet et al. 2014). Each photograph

or video can be stamped with the time and date, allowing cal-

culation of time intervals between consecutive captures at the

same location (Figure 35.4). From these data, overlap between

activity patterns of sympatric species may be deduced, either in

the entire study area or on specific points of interest (Harmsen

et al. 2009). In the latter case, the sites where the cameras are

placed should be chosen according to the goal of the study.

When focusing on interactions at the wildlife–livestock inter-

face, these sites could be water or feeding points designed for

livestock (Kukielka et al. 2013; Payne et al. 2016), livestock facil-

ities to witness potential wild boar visits to outdoor pig farms

(Wu et al. 2012; Kukielka et  al. 2013; Carrasco-Garcia et  al.

2015; Payne et al. 2016), baiting sites for wild pigs (Figure 35.5)

or points for which the effectiveness of management measures

Figure 35.3 Pictures of free-ranging white-lipped peccaries with skin
affected by skin lesions, taken in the Calakmul Biosphere Reserve, southern
Mexico (photo by Rafael Reyna).

Figure 35.4 Pictures of wild boars obtained at a drinking spot with camera

trap, indicating time and date (photos by Ariane Payne).

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