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.