System specific biology
In the wild pig system, pigs exhibited a higher probability of contact
at locations along certain linear landscape features, such as fences,
trails, and ditches, compared to their resource selection patterns. It
appeared that pigs used fence lines, trails and ditches as corridors to
transit between habitats, leading to encounters. In addition to transit
corridors, some large ditches in the FL site may contain water after
major rainfall events, thus providing attractive water resources for
wild pigs. Several previous studies have suggested preferences for
resources closer to linear features by pigs, such as power lines (Clontz
et al. 2021) or agricultural edges (Snow et al. 2017), indicating use of
these areas may be resource driven. Similar findings in other systems
indicate early-seral vegetation on linear features like seismic lines,
pipelines and industrial access roads provide forage for herbivore
ungulates, resulting in increased interspecific contact and competition
between these species (MacDonald et al. 2020).
Differences between contact- and individual-RSF were also found in
relation to strongly preferred landscape features including wetlands,
water, and food resources (concordant with previous work (Thurfjell et
al. 2009, Paolini et al. 2018)). Contacts, however, occurred at wetland
habitats and water less than expected by chance. In the study systems,
animals displayed a tendency to segregate their use of preferred
resources, suggesting a potential dominance or monopolization of these
resources. This observation implies a resource despotic pattern rather
than a free distribution (Harper 1982).
Supplemental feeding can provide wildlife with an abundant and
predictable food source on the landscape, leading to changes in their
foraging behaviors and population aggregation at the feeding sites
(Becker et al. 2018). Thus, supplemental food can often facilitate
direct contacts among individuals with implications for disease
transmission and other ecological interactions. In the TX sites, bait
piles significantly attracted wild pigs (Kilgo et al. 2021). In contrast
to cattle supplements in FL, contact locations were also biased towards
pig bait in TX indicating that these management techniques could affect
contact driven ecological processes, like disease transmission (Yang et
al. 2021b). In this case, baiting was used as an attractant for removal
strategies, which may reduce disease concerns.