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Kilgo JC, Vukovich M, Cox KJ, Larsen M, Mims TT, Garabedian JE. Assessing whole-sounder removal versus traditional control for reducing invasive wild pig (Sus scrofa) populations. PEST MANAGEMENT SCIENCE 2023; 79:3033-3042. [PMID: 36966457 DOI: 10.1002/ps.7478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 03/20/2023] [Accepted: 03/26/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Trapping is commonly used as the primary management tool in attempts to reduce invasive wild pigs (Sus scrofa), but traditional trapping techniques are often ineffective. However, recently developed traps permit the capture of entire social groups (sounders) of wild pigs, and the strategy of whole-sounder removal may achieve more effective control. Our objective was to experimentally compare traditional control (TC; primarily traditional trapping, but including hunting with dogs, and opportunistic shooting) and whole-sounder removal (WSR) strategies by assessing density reduction and removal rate after 1 and 2 years of treatment. RESULTS After 1 year of trapping, average wild pig density on WSR units declined 53% and remained stable after the second year, whereas on TC units, pig density did not differ after trapping, although it declined 33% and remained stable after the second year of trapping. The median removal rate (percentage of uniquely marked pigs present at the beginning of each year that were removed) was 42.5% for WSR units and 0.0% for TC units during 2018 and were 29.6% from WSR units and 5.3% from TC units during 2019. CONCLUSIONS WSR removal was more effective at reducing wild pig density than TC, but factors such as previous exposure of this population to traditional traps and the lack of barriers to recolonization from surrounding areas may have reduced WSR efficacy. WSR can effectively reduce wild pig density to a greater extent than TC, but managers should recognize the additional time and expense necessary for implementation. Published 2023. This article is a U.S. Government work and is in the public domain in the USA. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- John C Kilgo
- USDA Forest Service, Southern Research Station, New Ellenton, SC, USA
| | - Mark Vukovich
- USDA Forest Service, Southern Research Station, New Ellenton, SC, USA
| | - Kyle J Cox
- USDA Forest Service, Southern Research Station, New Ellenton, SC, USA
| | - Michael Larsen
- USDA Forest Service, Savannah River, New Ellenton, SC, USA
| | - Thomas T Mims
- USDA Forest Service, Savannah River, New Ellenton, SC, USA
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Snow NP, Glow MP, Lavelle MJ, Fischer JW, Cook SM, Lutman M, Foster JA, VerCauteren KC. Dry and Unwary are Best Conditions for Baiting Wild Pigs (Sus scrofa). Appl Anim Behav Sci 2022. [DOI: 10.1016/j.applanim.2022.105777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pepin KM, Brown VR, Yang A, Beasley JC, Boughton R, VerCauteren KC, Miller RS, Bevins SN. Optimizing response to an introduction of African swine fever in wild pigs. Transbound Emerg Dis 2022; 69:e3111-e3127. [PMID: 35881004 DOI: 10.1111/tbed.14668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/22/2022] [Accepted: 07/24/2022] [Indexed: 11/28/2022]
Abstract
African swine fever virus (ASFv) is a virulent pathogen that threatens domestic swine industries globally and persists in wild boar populations in some countries. Persistence in wild boar can challenge elimination and prevent disease-free status, making it necessary to address wild swine in proactive response plans. In the U.S., invasive wild pigs are abundant and found across a wide range of ecological conditions that could drive different epidemiological dynamics among populations. Information on size of control areas required to rapidly eliminate ASFv in wild pigs and how this area should change with management constraints and local ecology are needed to optimize response planning. We developed a spatially-explicit disease transmission model contrasting wild pig movement and contact ecology in two ecosystems in southeastern U.S. We simulated ASFv spread and determined optimal response area (reported as radius of a circle) for eliminating ASFv rapidly over a range of detection times (when ASFv is detected relative to true date of introduction), culling capacities (proportion of wild pigs in the culling zone removed weekly), and wild pig densities. Large radii for response areas (14 km) were needed under most conditions but could be shortened with early detection (≤ 8 weeks) and high culling capacities (≥ 15% weekly). Under most conditions ASFv was eliminated in less than 22 weeks using optimal control radii, although ecological conditions with high rates of wild pig movement required higher culling capacities (≥ 10% weekly) for elimination within one year. Results highlight the importance of adjusting response plans based on local ecology and show wild pig movement is a better predictor of optimal response area than numbers of ASFv cases early in the outbreak trajectory. Our framework provides a tool for determining optimal control plans in different areas, guiding expectations of response impacts, and planning resources needed for rapid elimination. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Kim M Pepin
- National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, 4101 Laporte Ave., Fort Collins, CO, 80526
| | - Vienna R Brown
- United States Department of Agriculture, Animal and Plant Health Inspection Services, Wildlife Services, National Feral Swine Damage Management Program, Fort Collins, CO
| | - Anni Yang
- National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, 4101 Laporte Ave., Fort Collins, CO, 80526.,Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, Colorado, 80523, US
| | - James C Beasley
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources, University of Georgia, PO Drawer E, Aiken, South Carolina, 29802, US
| | - Raoul Boughton
- Archbold Biological Station's Buck Island Ranch, 300 Buck Island Ranch Road, Lake Placid, FL, 33852, US
| | - Kurt C VerCauteren
- National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, 4101 Laporte Ave., Fort Collins, CO, 80526
| | - Ryan S Miller
- Centers for Epidemiology and Animal Health, Veterinary Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, 2150 Center Ave., Fort Collins, CO, 80526
| | - Sarah N Bevins
- National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, 4101 Laporte Ave., Fort Collins, CO, 80526
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Schlichting PE, Boughton RK, Anderson W, Wight B, VerCauteren KC, Miller RS, Lewis JS. Seasonal variation in space use and territoriality in a large mammal (Sus scrofa). Sci Rep 2022; 12:4023. [PMID: 35256629 PMCID: PMC8901613 DOI: 10.1038/s41598-022-07297-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 01/25/2022] [Indexed: 11/12/2022] Open
Abstract
An individual’s spatial behavior is shaped by social and environmental factors and provides critical information about population processes to inform conservation and management actions. Heterogeneity in spatial overlap among conspecifics can be evaluated using estimates of home ranges and core areas and used to understand factors influencing space use and territoriality. To understand and test predictions about spatial behavior in an invasive large mammal, the wild pig (Sus scrofa), we examined variation in space use between sexes and seasons. We predicted that if animals were territorial that there would be a reduction in space-use overlap when comparing overlap of home ranges (HR–HR), to home ranges and core areas (HR–CA), and in-turn between core areas (CA–CA). Home ranges and core areas were estimated for 54 wild pigs at Buck Island Ranch, FL from GPS telemetry data. Overlap indices were calculated to estimate the strength (space-use overlap) and number of potential interactions within three wet seasons (June–October) and two dry seasons (December–April). Among sexes, home range size did not vary seasonally, and males exhibited larger home ranges compared to females (M = 10.36 ± 0.79 km2 (± SE), F = 3.21 ± 0.16 km2). Strength of overlap varied by season with wild pig home ranges overlapping more during the dry season. Males interacted with a greater number of individuals of both sexes, compared to females, and exhibited greater strength of overlap during the dry season. Consistent with our predictions, wild pigs appeared to exhibit territorial behavior, where strength of overlap decreased when comparing HR–HR to HR–CA and HR–CA to CA–CA. Our framework can be used to understand patterns of space use and territoriality in populations, which has important implications in understanding intraspecific interactions and population processes, such as how pathogens and parasites might spread within and among populations.
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Kilgo JC, Garabedian JE, Vukovich M, Schlichting PE, Byrne ME, Beasley JC. Food resources affect territoriality of invasive wild pig sounders with implications for control. Sci Rep 2021; 11:18821. [PMID: 34552124 PMCID: PMC8458451 DOI: 10.1038/s41598-021-97798-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/30/2021] [Indexed: 11/13/2022] Open
Abstract
Interest in control methods for invasive wild pigs (Sus scrofa) has increased due to their range expansion, population growth, and an improved understanding of their destructive ecological and economic effects. Recent technological advances in traps for control of pig populations facilitate capture of entire social groups (sounders), but the efficacy of “whole-sounder” trapping strategies is heavily dependent on the degree of territoriality among sounders, a topic little research has explored. We assessed territoriality in wild pig sounders on the Savannah River Site, South Carolina, USA, and examined whether availability of food resources provided by a municipal-waste landfill affected among-sounder territoriality. We estimated utilization distribution overlap and dynamic interactions among 18 neighboring sounders around a landfill. We found that although neighboring sounders overlapped in space, intensity of use in shared areas was uniformly low, indicating territorial behavior. Neighbors tended to share slightly more space when closer to the landfill waste cells, indicating availability of a super-abundant resource somewhat weakens the degree of territoriality among sounders. Nevertheless, we conclude that sounders behaved in a generally territorial manner, and we discuss implications for whole-sounder trapping programs, particularly near concentrated resources such as landfills and crop fields.
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Affiliation(s)
- John C Kilgo
- USDA Forest Service, Southern Research Station, P.O. Box 700, New Ellenton, SC, 29809, USA.
| | - James E Garabedian
- USDA Forest Service, Southern Research Station, P.O. Box 700, New Ellenton, SC, 29809, USA
| | - Mark Vukovich
- USDA Forest Service, Southern Research Station, P.O. Box 700, New Ellenton, SC, 29809, USA.,USDA Forest Service, Shawnee National Forest, 602 North First St., Vienna, IL, 62995, USA
| | - Peter E Schlichting
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources, University of Georgia, P.O. Drawer E, Aiken, SC, 29802, USA.,Illinois Department of Natural Resources, 1 Natural Resources Way, Springfield, IL, 62702, USA
| | - Michael E Byrne
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources, University of Georgia, P.O. Drawer E, Aiken, SC, 29802, USA.,School of Natural Resources, University of Missouri, Columbia, MO, 65211, USA
| | - James C Beasley
- Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources, University of Georgia, P.O. Drawer E, Aiken, SC, 29802, USA
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