{
  "title": "Wildlife fencing and road-kill mitigation: historical research excerpt",
  "compiledBy": "Fence Advisors",
  "reviewedAt": "2026-10-03",
  "referencePeriod": "2016 meta-analysis; included research through April 2015; FHWA 2008 context",
  "compilationLicense": "https://creativecommons.org/licenses/by/4.0/",
  "licenseNote": "Original compilation and graphics only; does not relicense third-party documents or trademarks.",
  "sources": [
    { "id": "meta", "label": "Rytwinski et al., PLOS ONE (2016), DOI 10.1371/journal.pone.0166941", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC5117745/", "locator": "Abstract; Results; Figure 6; limitations and study-design discussion" },
    { "id": "fhwa", "label": "FHWA Wildlife-Vehicle Collision Reduction Study (2008), Chapter 8", "url": "https://www.fhwa.dot.gov/publications/research/safety/08034/08.cfm", "locator": "Wildlife Fencing: Direct Benefits, Undesirable Effects and maintenance" },
    { "id": "handbook", "label": "FHWA Wildlife Crossing Structure Handbook (March 2011)", "url": "https://www.fhwa.dot.gov/clas/ctip/wildlife_crossing_structures/", "locator": "Publication scope and notice: not a standard, specification or regulation" }
  ],
  "studyCounts": { "includedStudies": 50, "effectSizes": 99, "northAmericanStudies": 41 },
  "largeMammalReductionsPercent": [
    { "measure": "Fencing with crossing structures", "reductionPercent": 83 },
    { "measure": "Animal detection systems", "reductionPercent": 57 },
    { "measure": "Wildlife reflectors", "reductionPercent": 1 }
  ],
  "allTaxaFencingWithOrWithoutCrossingsReductionPercent": 54,
  "limitations": [
    "Historical evidence, not a new 2026 experiment or a current national road-kill count.",
    "Large-mammal results and the all-taxa fencing result are different subsets and cannot be combined as interchangeable estimates.",
    "These are synthesized study effects with uncertainty and heterogeneous designs; no claim of a fixed result for every project.",
    "Roadside exclusion systems with crossing structures are not backyard deer fences, livestock fences or a proof of a product's effectiveness.",
    "Point estimates are not a significance ranking; consult Figure 6 for confidence intervals.",
    "Escape routes, crossings, fence ends, species, terrain and ongoing maintenance are part of the safety and ecological decision."
  ]
}