Connecting the Dots: Behavioral State Resource Selection in Wild Pigs in the Southeast United States
Invasive wild pigs (Sus scrofa) are behavioral generalists that have the potential to alter ecosystems across broad spatial scales. Elucidating the correlation between wild pig behavior and landscape attributes can aid in the advancement of management strategies for controlling populations.
Using GPS data from 49 wild pigs in the southeastern U.S., we used movement characteristics to distinguish and define behaviors and explore the connection between these behaviors and resource selection for both females and males between two distinct seasons based on forage availability. We extracted three biologically relevant behaviors of wild pigs from our movement data using hidden Markov models, which we inferred to represent resting, foraging, and traveling behavioral states. We then used multi-scale resource selection functions to quantify resource selection at the population and home-range scales for each behavioral state.
Females demonstrated a crepuscular movement pattern in the high-forage season and a variable pattern in the low-forage season, with increased traveling and foraging activity during the daytime and evening hours, while males consistently demonstrated a nocturnal pattern across both seasons. At the population scale, wild pigs selected for forest vegetation types (i.e., upland pines, upland hardwoods, bottomland hardwoods) in both the low- and high-forage seasons, likely reflecting their ubiquitous establishment throughout the landscape. At the home-range scale, wild pigs selected for bottomland hardwoods and dense canopy cover in all behavioral states. In addition, males demonstrated selection for a variety of vegetation types while foraging in the low-forage season compared to the high-forage season and demonstrated an increased use of linear anthropogenic features (e.g., roads) across seasons while traveling.
Our results demonstrate male and female pigs exhibit clear differences in movement behavior. Further, although wild pigs can establish populations and home ranges in an array of landscapes and habitat types, there are key resources associated with common behaviors they select consistently at a fine scale that can be targeted in conservation and management programs across their invasive range.
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This is a list of supplementary files associated with this preprint. Click to download.
Additional file 1 (“Additional File 1.pdf”): Table S1.Model selection results for (a) female wild pigs in the low-forage season, (b) female wild pigs in the high-forage season, (c) male wild pigs in the low-forage season, and (d) male wild pigs in the high-forage season from hidden Markov models (HMMs) testing for the number of movement states and additive effect of time of day on the transition probabilities among movement states. Only two and three states were tested because we did not see a biologically significant benefit to discern a fourth behavioral state for the purpose of this paper.
Posted 18 Aug, 2020
Connecting the Dots: Behavioral State Resource Selection in Wild Pigs in the Southeast United States
Posted 18 Aug, 2020
Invasive wild pigs (Sus scrofa) are behavioral generalists that have the potential to alter ecosystems across broad spatial scales. Elucidating the correlation between wild pig behavior and landscape attributes can aid in the advancement of management strategies for controlling populations.
Using GPS data from 49 wild pigs in the southeastern U.S., we used movement characteristics to distinguish and define behaviors and explore the connection between these behaviors and resource selection for both females and males between two distinct seasons based on forage availability. We extracted three biologically relevant behaviors of wild pigs from our movement data using hidden Markov models, which we inferred to represent resting, foraging, and traveling behavioral states. We then used multi-scale resource selection functions to quantify resource selection at the population and home-range scales for each behavioral state.
Females demonstrated a crepuscular movement pattern in the high-forage season and a variable pattern in the low-forage season, with increased traveling and foraging activity during the daytime and evening hours, while males consistently demonstrated a nocturnal pattern across both seasons. At the population scale, wild pigs selected for forest vegetation types (i.e., upland pines, upland hardwoods, bottomland hardwoods) in both the low- and high-forage seasons, likely reflecting their ubiquitous establishment throughout the landscape. At the home-range scale, wild pigs selected for bottomland hardwoods and dense canopy cover in all behavioral states. In addition, males demonstrated selection for a variety of vegetation types while foraging in the low-forage season compared to the high-forage season and demonstrated an increased use of linear anthropogenic features (e.g., roads) across seasons while traveling.
Our results demonstrate male and female pigs exhibit clear differences in movement behavior. Further, although wild pigs can establish populations and home ranges in an array of landscapes and habitat types, there are key resources associated with common behaviors they select consistently at a fine scale that can be targeted in conservation and management programs across their invasive range.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5