Use of Scupper-Modified Jersey Barriers by Small Wildlife Along a New Segment of I-49 in Southwestern Missouri

Details

• Alternative Title:
  Methods for Monitoring the Movement of Wildlife Through Concrete Barrier Gaps
• Creators:
  Ortega, Brock ; Woodie, Clara ; Shilling, Fraser ; Brehme, Cheryl
• Corporate Creators:
  Dudek & Associates
• Corporate Contributors:
  Missouri. Department of Transportation. Construction and Materials Division ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Cameras Camera Study Coverboard Study Ecology Ecosystems Environment Environmental DNA Fatalities Highway Design Jersey Barrier Mammals Median Barriers Road Kill Road Mortality Study Scupper Surveys Wildlife Crossings

  More +
• Publication/ Report Number:
  cmr-26-007
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Missouri
• Edition:
  Final Report
• Corporate Publisher:
  Missouri. Department of Transportation. Construction and Materials Division
• Abstract:
  This study evaluated the effectiveness of scupper-modified Jersey barriers in facilitating small wildlife movement across a newly constructed segment of Interstate 49 in southwestern Missouri. Traditional concrete median barriers can reduce wildlife-vehicle collisions through fewer crossing attempts but create impermeable barriers for small-bodied species, fragmenting habitats and limiting connectivity. To address this, the Missouri Department of Transportation installed wildlife median barriers featuring scupper openings designed to allow passage for amphibians, reptiles, and small mammals. The research employed a multi-method approach, including road mortality surveys, camera monitoring within scuppers, roadside and culvert camera studies, coverboard surveys, and environmental DNA (eDNA) sampling. Results indicate that scuppers are used by a variety of species; rodents were the most frequent users documented by cameras, while eDNA revealed a broader biodiversity signal, detecting amphibians, reptiles, and small mammals not observed visually. Amphibian and reptile roadkill patterns were strongly influenced by precipitation and temperature, with amphibian mortality peaking during rainfall events and reptile mortality concentrated in warmer months. Comparative analysis showed eDNA consistently detected more species than cameras, underscoring its value for identifying cryptic or nocturnal taxa. However, detection of eDNA at a roadway feature indicates the presence of genetic material but does not confirm live animal presence, residency, or use of the feature. Therefore, eDNA results should be interpreted as probabilistic indicators of recent regional presence and evaluated alongside complementary survey methods. Overall, scuppers in wildlife median barriers represent a cost-effective and promising mitigation strategy to provide small animal permeability between fragmented habitats bisected by roads, especially for small mammals. The use and effectiveness of scuppers for amphibians and reptiles requires further studies that validate their presence at scuppers. Combining structural innovations with controlled studies and integrated monitoring approaches inform future highway design standards and improve ecological connectivity.
• Format:
  PDF
• Funding:
  TR202312
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:450631c9f8c3bfe395dcd596f9cc09bf6daf4f41f93cae445e8675eeaebd96ff5ef09644d293204e75cd4a3c3ff2aa83bcbaf52502ea1f86824f2f45514802b2
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/93015/dot_93015_DS1.pdf
• File Type:
  [PDF - 17.72 MB ]